Apple's App Store turns five this week (it first opened on July 10, 2008), and to celebrate, many of the biggest and best apps - including games - seem to be going on sale for, well, nothing.
Among the games currently available for free (the sale isn't official yet, so people are finding more games as they keep searching) include Sword & Sworcery, Infinity Blade 2, Where's My Water, Tiny Wings and Badland.
If any of those games have an iPad version, they're free as well.
Get on it.
UPDATE - Here's a list cataloguing everything that's been found so far.