Window always in background: how?

Is there any way of making a window stay in the back no matter what, as if it was stuck to the background? I want to do this with my adium since there is no use to have the contact window anywhere but the background, and it would have been kind of cool if it stuck to the background somehow xD
I'm running Mac OS 10.6.1
Thanks in advance!

 

Doesn't work for all windows ;(

Yeah, that's exactly what I wanted, only i wanted it to go below all other windows not only the ones belonging to adium itself, and as far as I'm concerned I believe there is no way doing that through the program itself. I hoped that there would be some kind of application or setting that could place one window below all others even if you highlight it.