My Starbucks Card is a new app over at the Windows Phone Marketplace that lets you use your Starbucks card right from your Windows Phone. No need to fumble around for the card, just run My Starbucks Card and your card can be scanned straight from your Windows Phone.
When you first launch My Starbucks Card you will be prompted to enter your card number and Starbucks.com credentials. A virtual card will be generated on My Starbucks Card's main screen and the app will even pull up your current balance.
While My Starbucks Card isn't an "official" Starbucks app, it does looks like it would come in handy if you are a Starbuck's frequent flyer. The app will run you $.99 and you can grab it here at the Windows Phone Marketplace.