PHILADELPHIA--(BUSINESS WIRE)--Comcast today announced a #SignMyTweet event with NASCAR driver Danica Patrick. In the midst of her third full-time NASCAR Sprint Cup Series season, Patrick will sign fan tweets during a two-hour live autograph session days before the NASCAR Sprint Cup Series Coca-Cola 600 at Charlotte Motor Speedway. Fans can submit Tweets starting Friday, May 15, for a chance to receive an oversized version of their own Tweet, signed by Patrick. The event is hosted by XFINITY, C