From an e-mail apparently sent from Gowalla CEO Josh Williams to investors, as reported by All Things D. Location-based Foursquare competitor Gowalla has been acquired by Facebook, says CNNMoney, which cites “a source close to Gowalla.”

The service wasn’t able to keep up with Fourquare’s user growth and “recently shifted directions, recasting itself as a travel guide,” according to CNNMoney. Gowalla’s features will reportedly be implemented into Facebook’s new Timeline design.