Bazaar has a great feature where  you can quickly do a

bzr ignore <file>

And it gets added to a local .bzrignore file in your branch root. Obviously very handy for things like sqlite development data. There is of course a global ignore feature, with many presets for things like object files, python compiled byte code etc.

Olive is a nice gtk front end to bzr include in bzr-gtk. One thing thats annoying though,  especially when you have lots of .pyc files all over the place is that it doesnt hide ignored files. Five minutes of hacking later and I had a patch to fix this, a quick chat in #bzr and its already been commited. Open source is just fantastic.