Here's a tool that works kind of like iwit with with less flashy stuff. Drag this to your bookmarks to use it:
Dumbwit
Experimental Profile support. Grab a shot of profiles!
Dumbwitprofile
New! iPhone/iPod Touch support! See here for instructions!
Currently, the comment does nothing but that may change. Depends on how fast the real one gets fixed! This is roughly equivilent to iwit's "Private" option. The directory is not listable or searchable. The URL is based off the current epoch time and a random number, so I can't guarantee that someone can't find an old one by luck.
I can be reached at scott (at) iamscott (dot) net if you have any questions, comments, or manage to break it.
If you are using noscript in Firefox, you'll need to set up at least urbandead.com in the allowed exceptions for xss (cross-site scripting), and possibly iamscott.net as well.
Updates:
6/7/2009:
I've fixed the issues with udtoolbar prettiness and the  characters all over. If you have udtoolbar, the pretty display should be retained in the dumbwit. If you don't, it should display Classic style. I've updated all the past entries for the fix, so they should work. If your entry is now broken in some way, drop me an email with a link and I'll take a look at it.
The current leading cause of issues is various addons and extensions that do strange things. It may need some styling information or something that the dumbwit doesn't retain. If you have something that comes across broken or strange, send me an email with the link and what addons you're using, and I'll see about updating it to support them better.