I am running 12.04 and have followed the instructions here:
Is it possible to have a different background for each workspace?
to get a different wallpaper per workspace. It works by disabling nautilus' drawing of the desktop and enables the Compiz wallpaper plug-in. But since I've done that my conky will not longer appear.
Here's the relevant portion of it:
background yes
use_xft yes
xftfont Sans:size=10
xftalpha 0.9
update_interval 1.0
total_run_times 0
own_window yes
own_window_type desktop
own_window_title "conky"
own_window_hints undecorated,below,sticky,skip_taskbar,skip_pager
double_buffer yes
minimum_size 180 5
maximum_width 200
draw_shades no
draw_outline no
draw_borders no
draw_graph_borders no
default_color white
default_shade_color red
default_outline_color green
alignment top_right
gap_x 12
gap_y 28
no_buffers yes
uppercase no
cpu_avg_samples 2
override_utf8_locale no