Windows only: Freeware application PatchOnClick updates large files by creating patches from the new file and applying those patches to old files with a dead simple interface. At first blush, this may seem like a tool that a normal user has very little use for, but FreewareGenius explains its usefulness perfectly:

I thought this program was a really nice touch to add. Go download it and play around and check out the full story at Life Hacker.