Mac OS X Services have been around for awhile, but not many people use them. Under the title of any program in the upper left of the menu bar, you'll find an option for Services, which brings up a pull-down menu of any services that are appropriate to the program at hand. This can be a real time saver.
I use TextEdit for writing my TUAW posts, and it's always running. Recently, I found a neat service that works wonders for TextEdit and (I'm sure) a bunch of other text editors. It's free for the downloading from Ron Fleckner in Melbourne, Australia. What you'll get is a ZI
