The Mars Real Chocolate Relief has been a great ongoing freebie! If you haven't done so yet, go sign up for your coupon for a free chocolate bar from Mars here. There's a limit of 4 per household for the giveaway period. yummy!
In addition to that, Amazon is giving away one free download (valued at $1.29) to everyone in celebration of their twitter reaching 1 million followers. The place, and instructions, can be found here. What a fun freebie!