Some more gems to run in KDE:
OpenOffice.org - A free, open-source competitor for Microsoft Office. Use the OpenOffice.org 1.0.3 for Mac OS X (X11) installer, then run '/Applications/OpenOffice.org1.0.3/program/soffice' from within KDE.
XMAME - Arcade machine emulator. Download the sources and compile using this makefile, which worked okay on my setup (with gcc3.3). Read the documentation for the rest of the setup instructions.