WindowBlinds - About six months ago I started using Windows XP full-time at work, moving from a Gentoo Linux installation. Part of the reason was that we got some snazzy new workstations (dual xeon, tons of memory, dual monitor) that I didn’t want to fight with a linux install. (Too old for that.) Part of the reason was that we were going to do pair programming, at least PT, and only one other person knows linux.
It went surprisingly well, particularly since I haven't used a Windows desktop for working in about five years. Windows XP is quite stable and since I really don't ask much from my OS/WM I didn't miss much. One of the exceptions was rolling up windows to a title bar -- one double-click and the window disappears, leaving only the title bar. Another double-click and it reappears. Most window managers under X do this, at least the ones that I've used, and I've grown very fond of it. XP doesn't do this -- double-click expands the window to fullscreen, another restores the window to its previous size. Yech.
After bitching about how this was missing and I couldn't find any utilities to do this (my Windows googling skillz need some work) one of my co-workers found a utility called WindowBlinds. Its main purpose is themes/skins, which I don't really care about (although I am using the 'Mac' theme just because things take up less room). But even the freeware version has the window rollup ability. Hooray!
The program itself is fairly easy to setup, hasn't caused any problems yet and looks nice. You also get the nice side-effect of having a right-click on a window's title bar minimize the whole window -- great, I hate having to aim for the minimize button. If you use the free version you just get a nag at startup and/or every day or two about the program: no problem for me.
(And to preempt any suggestions: no, getting a Mac is not an option. Not yet...)