Following, last weeks, Foursquare "check-in photos" feature, a developer has made a Web app called "FlickSquare" that helps you automatically post your Foursquare checkin photos to your Flickr account automatically!
All you need to do is sign into your Foursquare account, connect with FlickSquare, and finish by telling Flickr to let the app access your account. From now on, all new photos check-ins should be mirrored on Flickr.
FlickSquare also tags the Flickr uploads with the Foursquare venue machine tag, which create a rich resource of cross-linked venues and photos.
More Info: FlickSquare