Fx only. Used code from Glasstube by Lottel@userstyles, thanks!
Works for me with Vista/Aero, Fx 3.6*, Stylish 1.0.8, Glasser 3.5.2.

Better shots:
http://img130.imageshack.us/img130/8484/fullj.png
http://img404.imageshack.us/img404/9876/39873021.png

04/21/10 - added wiki.mozilla.
05/15/10 - due to the site changes. There's more to be done, as time permits, but it's glassed for now. I don't write, i read. So, made the left panel small and show on hover. If you want to hide it all together, start a discussion and i will help.
06/09/10 - made the Wiki logo image small, fits nicely in the top left corner, shows on hover (for those who need to get to the home page).
07/25/10 - https://wiki.mozilla bg for readability, cleaned out some left over corners and borders. Fixed a few things for http://en.wiktionary.org
10/04/10 - hid/changed some borders, changed the search image, etc. - small touchups.