In my spring cleaning of my social networking accounts, I have decided to delete my foursquare account. I tried both the iPhone and android foursquare applications and, personally, I don't find a use for it. I don't really want to manually "check-in" to a place, just for the purpose of the check-in.
I haven't used Yelp's check-in feature, but I could see it being more useful than foursquare's, as I assume I could add a review at the same time. Unfortunately, Yelp's check-in feature is not available in their Android application.