Starbucks Pledge5 For more details.

FREE tall brewed coffee @ Starbucks on Jan 21-25!!
All you need is to pledge to volunteer 5 hours of your time.

From January 21, 2009 through January 25, 2009, when you pledge 5 hours of volunteer time, Starbucks will salute you with a free Tall brewed cup of coffee in participating U.S. Starbucks stores. Not valid at airports or Barnes & Noble locations.
It looks like you send them your email address, you fill out a pdf. pledge card on what you plan to do, then print and bring to the store.