Keywurl is a nifty little Safari plugin that adds simple keyword search to the address bar. Say you wanted to pull up the Wikipedia entry for hacks: just type “wiki hacks” into the address bar. Looking for photos tagged with makerfaire? “flickr makerfaire” will take you to the appropriate place.
The latest beta version for Leopard allows you to right click on any form field and add a search shortcut keyword for it. This would easily let you add keywords like “hacks” or “slashdot” that would let you query for articles on your favorite sites. Unfortunately, there isn’t a Tiger build of this version yet, so revision slackers like me will have to wait. You can also get at the keyword settings manually through a new button in the Safari preferences panel.
I haven’t been using this long enough to tell if I’m going to keep it, but so far it’s really promising. At the very least, it sends me to the right place when I type in a search term into the address bar instead of the search bar by accident.