Frozenbyte Games is hosting a build-your-own indie game sale over at
hugeseals.com. When you log in at hugeseals with your Steam account you will be able to pick up to five games that you want to receive discount coupons for. The relevant coupon codes will be added to your account on hugeseals, after which you can redeem them in Steam. There are also a couple of other features, like getting a free game when you've used three coupons, which is cool.
You can find their promo video
here and their FAQ
here. If you want a list of the games involved and the magnitude of the discounts, you can find that
here.
Personally, I'm really tempted by Awesomenauts and Terraria, and maybe FTL.
Happy hunting! ^_^