Subversion does a good job by ignoring most of build/temporary/unwanted files by default.
However, there is one exception still existing at least in Subversion 1.6: Python egg folders. All folders whose name ends up with .egg-info should not committed or considered in version controlling actions. your.package.name.egg-info folder is generated inside your Python egg source folder when you run setup.py / setuptools.
If you are working with Python source code eggs, add the following line to your ~/.subversion/config
global-ignores = *.o *.lo *.la #*# .*.rej *.rej .*~ *~ .#* .DS_Store *.egg-info *.pyc *.pyo .project .pydevproject
Otherwise development tools like Mr. Developer might get confused.