I'm officially announcing here for the first time the upcoming release of our first update: ThreadBound 2.0! It will have more polished graphics and animation, and we're currently in the process of integrating it with Open Feint, which is sort of the iPhone equivalent of Xbox Live.
There are a couple other options such as Scoreloop, but Open Feint has a nice community feature which might help us get the word out about our game, and they also have the largest user base at the moment. It also has an achievements systems that works very much like on Xbox Live, and we're adding a whole whack of achievements that can be unlocked that range from trivial to nigh-impossible (such as beating my score >:D). You'll be able to submit your scores as well.
Up until a couple of days ago, Open Feint was charging developers for the service based on number of users (and we were going to go with it anyway; like Mr. Hammond, we've spared no expense). Now they've decided to make the program free for independent developers, which is great news, assuming the community doesn't consequently get flooded by a bunch of iFart players.