I recently had my birthday and enjoyed a few things for free, and I heard a little later than I would've liked about other birthday giveaways. So I figured I'd start a compilation here. If you know anything free that you'd like me to add, feel free to leave a comment. I will edit this as I find out more information:
Baskin Robbins has a birthday club. I got a free scoop of ice cream for my birthday. And they also send occasional emails with coupons. I also got a $3 coupon off an ice cream cake.
Dairy Queen has a sign-up that asks for your birthday. I just signed up, so I'm not sure if I would've got something for free for my birthday, but for signing up you can buy one blizzard and get one free.
Black Angus has a "Prime Club." I signed up the other day and got an email with a coupon and another that said, "Sorry we missed your birthday. Here's a steak on us." Sweet.
Red Robin emails a coupon for a free burger on your birthday, and they also email you coupons throughout the year. Joe and I got a free appetizer for no apparent reason not too long ago.
Denny's has a breakfast club I just signed up for. They say they email you offers, and for joining, I received a 20% off email.
13 Coins in Seattle has a dining club you can join for a fee. But Joe and I ate there in December and filled out a comment card (we REALLY liked the food), and since then, I received a letter thanking me for my comment, one for a free dessert for our anniversary, and one for a free dessert for my birthday. We haven't gone back yet, but we do plan to.
Shari's also has an e-club. I'm not sure yet what this entails, but it does ask for your birth month and says you'll receive birthday mailings.
And while looking for other fun birthday stuff, I ran across this list compiled by someone else: Birthday Deals and Discounts.
I also remember being told when I was in Arizona that a local theater let you see a movie for free for your birthday. I don't know if that's available here or where you live, but that might be something worth looking into.
A lot (if not all) of these require some sort of registration first, and if you are worried about spam email, set up a free email account through Hotmail or Yahoo or some other free hosting site and use that email for your registration. Also look carefully at what boxes are selected before sending your registration to avoid 3rd party emails. Then be sure to check your email for your email deals!