Starbucks has launched a new service that lets you buy a gift card for a friend through Twitter called Tweet A Coffee. The service requires you to sync your Starbucks account to your Twitter account. From there, you just need to tweet at the person that you want to buy a coffee for by saying “@Tweetacoffee to [your friend’s Twitter handle].” That user will receive a $5 gift card from your credit account. Your friend can redeem the gift card from his or her phone. This service is currently only available in the U.S. Once the recipient receives the gift card, Starbucks will e-mail the gift giver.