I use WindowBlinds. i only have the trial version right now, so I can't edit as much or make my own skins but Deviantart.com has a lot of good skins for it. From what I've seen so far if you get a good skin you can make windows semi transparent, or roll up into their menu. Here is a screenshot of my current desktop:
http://www.dmcs.us/mydesktop.jpg
notice at the bottom right thefinalfantasy.com site and up near te start menu at the to is google rolled up.