you know you can have fun with those backgrounds?
just place random files on there and give them names of stuf you wouldn't want other people to see if they used your computer, like "password list" or "+18"
then use the prt scr button edit it a bit
then you use that picture as your background and remove the files again
then all you need to do is allow someone to use your computer and watch them try to open those files

i myself made such a backgroudn once but nobody ever uses my laptop so i never got to use the background

hehe, i get it , clever that lol, only thing is... ONLY I USE MY PC !!! ...... and only i !!! or i'll kill !!!

I've done similar to a couple of the lads at work. I wait until they go to lunch, go to their machines, take a screen shot and save it. Set the screen shot as the wallpaper and then (here's the smart bit) set the taskbar to auto hide.

When they come back and unlock their machines they see their normal desktop but none of the icons work and clicking the start button does nothing (because it was hidden with the task bar).

W1NN0R

i did something like this on a website, i put an unclickable "admin area" icon on the main page

I do that thing where you flip the screen upside down. Its like ctr, alt and up or something, think it only works on xp machines. I always used to do it to the old people in computer class in the place I used to work

My other favourite is selotape across the laser on someone's mouse.