After installing and playing around with your Linux distribution you might end up with a load of installed dependences doing nothing but taking up space on your drive. With a cool little program you can find all packages that can be removed, deborphan.
This will give you a list of packages that are not used. You don’t need root access for this as it only reads the database.
You can use it like this:
apt-get purge `deborphan --guess-all` dpkg --purge `deborphan --guess-all` aptitude purge `deborphan --guess-all`