I'm not the developer, but I (and some coworkers) love this multiple desktop implementation.
Desktop Manager
http://wsmanager.sourceforge.net/
Very well done. I've been using it for a few months, and I noticed that the developer mentions:
"More importantly the icons for Desktop Manager suck IMHO. I am no graphic designer. If any kind soul feels they could do better, please drop me an e-mail. Ideally I'd like something as pretty as the icons on the new Mozilla FireFox browser. Eternal fame in the About Box shall be thine reward. "
I'd love to see this be prettier as well, that's my selfish reason for posting this. =)