That's like asking "anyone know any good apps?" OK, well there are a few good ones I can think of, many of which will be totally irrelevant to a lot of people...
SETI Dockling - controls SETI and gives a handy % done readout in the dock.
There's one that tells you if classic is running, I think it's called 'Clissic?' but I'm not sure.
There's one that lets you access all sys pref panes from the dock. I used to use it, but I don't any more. can't remember what it's called, either...
i dont use my dock, i use drag thing, which is an osx version of the clasic app. dragstrip. it also puts your trash can back on the desktop where it belongs. i higly recomend this app.