Item the first: If you’re getting 404 errors on your tag pages, try going to the Options > Permalinks page in wp-admin, and click the Update Permalinks button.
Item the second: There’s a bugfix release of UTW. Download Here! It should deal with the problem that contact form plugin thingy people were having – go to the Options > Tags page, and resave your options; then all should be good in the world.
Item the third: I’m looking for beta testers for taggish plugins I’m putting together for WordPress 2.3. If you’d like to beta test, and are using WordPress 2.3, send an email to beta [at] neato [dot] co [dot] nz.