AutoCheckin has been released.
It makes it simple to perform Facebook checkins, either automatically, based on heuristics, or manually by choosing a place nearby.
It’s ad-funded, like Converter Pro, but is more of a novelty app. If it catches on I’d be rather surprised, but stranger things have happened.
It’s in any case an interesting showcase of location and Facebook API features (interesting at least for geeks), that could be molded into completely different things.
Feel free to report “features”.