In another gracious move, the Humble Indie Bundle 3 has been updated with even more independent games. Everyone who already paid now has access to the Humble Indie Bundle 2 titles: Braid, Cortex Command, Machinarium, Osmos, and Revenge of the Titans -- free of charge!
For new customers, you'll need to pay above the average contribution amount, which is currently sitting at around five bucks. Seriously, that's next to nothing for hours and hours of entertainment. Steam and Desura keys are also included. If this doesn't push you over, I'm not sure what will.