If you havent seen this already, I recommend you check out this link and do all of those steps.
Five ways to slim down your Mac OS X install - Ars Technica
Other apps you can uninstall really depend on your needs and wants. I personally kept ical and mail since I prefer to have an app to check my mail instead of a webpage. You can substitute mail with lighter apps like thunderbird tho.
There are a lot of apps you can get rid of in the utilities folder. You most likely wont need the midi stuff, airport, boot camp, directory stuff, odbc, voice over, raid utility, color utilities, and maybe X11. I didnt install X11 to start with.
Other default apps you can get rid of are front row, font book, DVD player, and dictionary. There are apps you can replace like mail as stated before, safari, quicktime with vlc, ichat with adium, itunes, not sure what to repalce it with, but Im sure there are much lighter apps. If you dont use isync you can get rid of that too. After all the slimming, I was able to get to down around 5gb or so, but i kept some of the larger apps that could save more space.