I am not sure how many people still use Gowalla over FourSquare, but if you are still doing your checking in with this FourSquare competitor you will be pleased to know a Windows Phone 7 client is on the way.
The app is currently being polished by MacroPod and should be submitted to Marketplace soon.
An official app is apparently also on the way, but is almost certainly further off.
See more screen shots here.
Via WPSauce.com