My brother pointed me in the direction of this piece of software over the weekend. It’s pretty ruthless at locating and deleting old temporary files that just take up space on your computer
http://www.stevengould.org/software/cleanup/%5B/url%5D
I ran it over the weekend on our laptop and it found over 2GB of savings. Admittedly it removed all the cookies – so we lost some personalisation details (like where we live and automatic sign-in etc) on some sites, but you can confgure it to keep cookies if you prefer. If you want to keep your Most Recently Used lists you have to exclude them from the delete!
It’s 
to use (it gives a chance to make voluntary donations if you’re happy with it) and pretty quick and effective. First time you run it it gives the choice of running in demo mode so you can see what it is planning to delete (The result of my first run offered over 6GB of deletions – which included a lot of usenet stuff I preferred to keep). If you want to be even more rigorous it can remove all Favourites as well.
Oh yes, it has its own sound effect too!
