Conky is a free, light-weight system monitor for X, that displays any information on your desktop. It is tricky to configure it to display sharp graphics. Conky-colors makes it easier to do the job.

Here are my configuration files:
.conkyForecast.config
CACHE_FOLDERPATH = /tmp/
CONNECTION_TIMEOUT = 5
EXPIRY_MINUTES = 30
TIME_FORMAT = %H:%M
DATE_FORMAT = %Y-%m-%d
LOCALE =
XOAP_PARTNER_ID =
XOAP_LICENCE_KEY =
MAXIMUM_DAYS_FORECAST = 4
BASE_XOAP_URL = http://xoap.weather.com/weather/local/CAXX0504?cc=*&dayf=5&link=xoap&prod=xoap&par=&key=&unit=m
#BASE_XOAP_URL = http://xml.weather.com/weather/local/?cc=*&unit=m&dayf=10&link=xoap&prod=xoap&par=&key=&unit=m

conkymain
use_xft yes
xftfont Liberation Sans:size=8

update_interval 1
total_run_times 0
double_buffer yes
text_buffer_size 2048

own_window yes
own_window_type override
own_window_transparent yes
own_window_hints undecorated,below,sticky,skip_taskbar,skip_pager

minimum_size 185 0
maximum_width 185

default_color cccccc
draw_shades no

color0 white
color1 E07A1F
color2 white

alignment top_right
gap_x 25
gap_y 50

no_buffers no
net_avg_samples 2

override_utf8_locale yes

no_buffers yes

background yes

TEXT
${font Liberation Sans:style=Bold:size=8}SYSTEM $stippled_hr${font}
${voffset 2}${color0}${font OpenLogos:size=16}u${font}${color} Kernel: ${alignr}${color2}${kernel}${color}
${color0}${font StyleBats:size=16}A${font}${color} CPU1: ${font Liberation Sans:style=Bold:size=8}${color1}${cpu cpu1}%${color}${font} ${alignr}${color2}${cpubar cpu1 8,60}${color}
${color0}${font StyleBats:size=16}A${font}${color} CPU2: ${font Liberation Sans:style=Bold:size=8}${color1}${cpu cpu2}%${color}${font} ${alignr}${color2}${cpubar cpu2 8,60}${color}
${color0}${font weather:size=18}y${font}${color} CPU Temp: ${font Liberation Sans:style=Bold:size=8}${color1}${execi 120 /usr/bin/sensors|grep "CPU Temp"|cut -d"+" -f2|cut -d"(" -f1}
${color0}${font weather:size=18}y${font}${color} Board Temp: ${font Liberation Sans:style=Bold:size=8}${color1}${execi 120 /usr/bin/sensors|grep "Board Temp"|cut -d"+" -f2|cut -d"(" -f1}
${color0}${font StyleBats:size=16}g${font}${color} RAM: ${font Liberation Sans:style=Bold:size=8}${color1}$memperc%${color}${font} ${alignr}${color2}${membar 8,60}${color}
${color0}${font StyleBats:size=16}j${font}${color} SWAP: ${font Liberation Sans:style=Bold:size=8}${color1}$swapperc%${color}${font} ${alignr}${color2}${swapbar 8,60}${color}
${color0}${font StyleBats:size=16}q${font}${color} Uptime: ${alignr}${color2}${uptime}${color}
${color0}${font StyleBats:size=16}l${font}${color} Processes: ${color2}${alignr 13}CPU${alignr}RAM${color}
${goto 32}${top name 1}${font Liberation Sans:style=Bold:size=8}${color1} ${goto 124}${top cpu 1}${alignr }${top mem 1}${color}${font}
${goto 32}${top name 2}${font Liberation Sans:style=Bold:size=8}${color1} ${goto 124}${top cpu 2}${alignr }${top mem 2}${color}${font}
${goto 32}${top name 3}${font Liberation Sans:style=Bold:size=8}${color1} ${goto 124}${top cpu 3}${alignr }${top mem 3}${color}${font}
${goto 32}${top name 4}${font Liberation Sans:style=Bold:size=8}${color1} ${goto 124}${top cpu 4}${alignr }${top mem 4}${color}${font}

${font Liberation Sans:style=Bold:size=8}DATE $stippled_hr${font}
${alignc 45}${color2}${font Arial Black:size=30}${time %H:%M}${font}${color}
${voffset 4}${color0}${font RsbillsDng:size=20}O${font}${color}${voffset -4}${font Liberation Mono:size=8}${execpi 10800 DJS=`date +%_d`; cal | sed 's/^/${alignc} /' | sed s/" $DJS "/" "'${font Liberation Mono:style=bold:size=8}${color1}'"$DJS"'${color}${font}${font Liberation Mono:size=8}'" "/}${font}${font}

${font Liberation Sans:style=Bold:size=8}HD $stippled_hr${font}
${voffset 4}${color0}${font Weather:size=15}y${font}${color}${voffset -2} Temperature: ${font Liberation Sans:style=Bold:size=8}${color1}${execi 120 hddtemp /dev/sdc -n --unit=C}°C${color}${font}${alignr}${color2}/dev/sdc${color}
${voffset 4}${color0}${font PizzaDude Bullets:size=14}s${font}${color} Write: ${font Liberation Sans:style=Bold:size=8}${color1}${diskio_write}${color}${font}
${goto 30}${diskiograph_write 32,150 b7b370 ff3e00}
${voffset 4}${color0}${font PizzaDude Bullets:size=14}w${font}${color} Read: ${font Liberation Sans:style=Bold:size=8}${color1}${diskio_read}${color}${font}
${goto 30}${diskiograph_read 32,150 33846c 00c6ff}

${font Liberation Sans:style=Bold:size=8}NETWORK $stippled_hr${font}
${voffset 4}${color0}${font PizzaDude Bullets:size=14}O${font}${color} Up: ${font Liberation Sans:style=Bold:size=8}${color1}${upspeed eth0}${color}${font}
${goto 30}${upspeedgraph eth0 32,150 ff00ff ff0000}
${voffset 4}${color0}${font PizzaDude Bullets:size=14}U${font}${color} Down: ${font Liberation Sans:style=Bold:size=8}${color1}${downspeed eth0}${color}${font}
${goto 30}${downspeedgraph eth0 32,150 ffff00 00ff00}
${voffset 4}${color0}${font PizzaDude Bullets:size=14}N${font}${color} Upload: ${alignr}${color2}${totalup eth0}${color}
${voffset 4}${color0}${font PizzaDude Bullets:size=14}T${font}${color} Download: ${alignr}${color2}${totaldown eth0}${color}
${voffset 4}${color0}${font PizzaDude Bullets:size=14}a${font}${color} Local ip: ${alignr}${color2}${addr eth0}${color}
${voffset 4}${color0}${font PizzaDude Bullets:size=14}b${font}${color} Public ip: ${alignr}${color2}${execi 10800 ~/.scripts/ip.sh}${color}

conkyForecast.template
${voffset 5}${goto 10}${font ConkyWeather:style=Bold:size=40}[--datatype=WF]${font}
${voffset -60}${goto 100}${font Weather:size=40}y${font Arial Black:size=26}[--datatype=HT]/[--datatype=LT]${font}
${voffset 40}${goto 10}${font ConkyWindNESW:size=40}[--datatype=BS]${font}
${voffset 5}${goto 10}[--datatype=WS --imperial] – [--datatype=WD]
${voffset 20}${goto 10}${font Moon Phases:style=Bold:size=36}[--datatype=MF]${font}
${voffset 5}${goto 10}${color1}[--datatype=MP]
${voffset -165}${goto 100}${color1}${font Bitstream Vera Sans Mono:style=Bold:size=14}[--datatype=CT]${font}
${voffset 10}${goto 100}${color3}Location: ${color1}[--datatype=CN], [--datatype=CO]
${goto 100}${color3}Station: ${color1}[--datatype=OB]
${goto 100}${color3}Rain: ${color1}[--datatype=PC]
${goto 100}${color3}UV: ${color1}[--datatype=UI] – [--datatype=UT]
${goto 100}${color3}Humidity: ${color1}[--datatype=HM]
${goto 100}${color3}Dew Point: ${color1}[--datatype=DP]
${goto 100}${color3}Sunrise/Set: ${color1}[--datatype=SR] / [--datatype=SS]
${goto 100}${color3}Bar: ${color1}[--datatype=BR] – [--datatype=BD]
${voffset 25}${goto 15}Today${goto 100}[--datatype=DW --startday=1 --shortweekday]${goto 175}[--datatype=DW --startday=2 --shortweekday]${goto 250}[--datatype=DW --startday=3 --shortweekday]
${voffset 10}${goto 10}${font ConkyWeather:size=32}[--datatype=WF --startday=0 --endday=3 --spaces=3]${font}
${goto 15}[--datatype=CT --startday=0 --hideunits --centeredwidth=3]${goto 90}[--datatype=CT --startday=1 --hideunits --centeredwidth=3]${goto 170}[--datatype=CT --startday=2 --hideunits --centeredwidth=3]${goto 245}[--datatype=CT --startday=3 --hideunits --centeredwidth=3]
${voffset 15}${goto 15}[--datatype=HT --startday=0 --hideunits --centeredwidth=3]/[--datatype=LT --startday=0 --hideunits --centeredwidth=3]${goto 90}[--datatype=HT --startday=1 --hideunits --centeredwidth=3]/[--datatype=LT --startday=1 --hideunits --centeredwidth=3]${goto 170}[--datatype=HT --startday=2 --hideunits --centeredwidth=3]/[--datatype=LT --startday=2 --hideunits --centeredwidth=3]${goto 245}[--datatype=HT --startday=3 --hideunits --centeredwidth=3]/[--datatype=LT --startday=3 --hideunits --centeredwidth=3]
${color3}${font Bitstream Vera Sans Mono:size=7}${alignr 20}Last Update: [--datatype=LU]${font}

conkyforecast
# set to yes if you want Conky to be forked in the background
background yes

# X font when Xft is disabled, you can pick one with program xfontsel
#font 5×7
#font 6×10
#font 7×13
#font 8×13
#font 9×15
#font *mintsmild.se*
#font -*-*-*-*-*-*-34-*-*-*-*-*-*-*

# Use Xft?
use_xft yes

# Xft font when Xft is enabled
xftfont Bitstream Vera Sans Mono:size=9

# Text alpha when using Xft
xftalpha 0.8

# Update interval in seconds
update_interval 1.0

# This is the number of times Conky will update before quitting.
# Set to zero to run forever.
total_run_times 0

# Create own window instead of using desktop (required in nautilus)
own_window no

# Use double buffering (reduces flicker, may not work for everyone)
double_buffer yes

# Minimum size of text area
minimum_size 300 0
maximum_width 300

# Draw shades?
draw_shades yes

# Draw outlines?
draw_outline no

# Draw borders around text
draw_borders no
draw_graph_borders yes

# Stippled borders?
stippled_borders 8

# border margins
border_margin 4

# border width
border_width 1

# Default colors and also border colors
default_color white
default_shade_color black
default_outline_color white

# own window options
own_window yes
own_window_transparent yes
own_window_type override
own_window_hints undecorated,below,sticky,skip_taskbar,skip_pager

# Text alignment, other possible values are commented
#alignment top_left
#alignment top_right
#alignment bottom_left
#alignment bottom_right
alignment top_left

# Gap between borders of screen and text
# same thing as passing -x at command line
gap_x 10
gap_y 35

# Subtract file system buffers from used memory?
no_buffers yes

# set to yes if you want all text to be in uppercase
uppercase no

# number of cpu samples to average
# set to 1 to disable averaging
cpu_avg_samples 2

# number of net samples to average
# set to 1 to disable averaging
net_avg_samples 2

# Force UTF8? note that UTF8 support required XFT
override_utf8_locale yes

# Add spaces to keep things from moving about? This only affects certain objects.
use_spacer right

# colours
color1 white
# light blue
color2 6892C6
# orange
#E77320
color3 FC8820
# green
color4 78BF39
# red
color5 CC0000

text_buffer_size 2048

# variable is given either in format $variable or in ${variable}. Latter
# allows characters right after the variable and must be used in network
# stuff because of an argument

# stuff after ‘TEXT’ will be formatted on screen

TEXT
${offset -5}${color3}${font StyleBats:style=CleanCut:size=12}q ${voffset -2}${font Bitstream Vera Sans Mono:style=Bold:size=11}Weather${font} ${hr}${color1}
${execpi 1800 conkyForecast –location=CAXX0504 –template=/home/zhibin/conky/conkyForecast.template}