If you go to Starbucks even semi-often you may as well register a rewards card with them. A rewards card will earn you free drinks and other free stuff the more you go to Starbucks. Plus you get a free drink on your birthday. Click here to register your card. You can put any balance on your card that you want. I just did $10. That should hold me over for a few visits (not for the more expensive drinks, but for coffee) and then I get the free birthday drink and other rewards.

