I just have to point you all at this cracking little utility I came across the other day.
It also not only gets rid of temp files from websites you've visited but resets the index.dat files which actually store details of every site you've ever visited even if you think you've cleaned the rest up. Resetting the index.dat files is not a trivial task for the average user as the system protects them and you have to boot up in safe mode or from a diskette and do it in Dos.
First time round it found over 1000 redundant entries in my Windows Registry and got rid of 8000 unwanted files from my C drive. My PC is more stable, faster, uses less memory now and the CPU running temp has actually dropped by 2 degrees from 56C to 54C.
I know, I sound like a snake oil salesman but it really is that good and it's free!