BleachBit

When your computer is getting full, BleachBit quickly frees disk space. When your information is only your business, BleachBit guards your privacy. With BleachBit you can free cache, delete cookies, clear Internet history, shred temporary files, delete logs, and discard junk you didn't know was there. Designed for Linux and Windows systems, it wipes clean thousands of applications including Firefox, Adobe Flash, Google Chrome, Opera, and more. Beyond simply deleting files, BleachBit includes advanced features such as shredding files to prevent recovery, wiping free disk space to hide traces of files deleted by other applications, and vacuuming Firefox to make it faster. Better than free, BleachBit is open source.