Let them have it. only a small group of people even know what foursquare is. This hoopla over how close the two products are, is probably the highest level of notoriety that Foursquare has ever seen. They probably just got a whopping 14 downloads in one day from curious people who just had to see WTF people are talking about.
See I have no idea how to spell 4square.. at all.. I can spell Gowalla, but I am a freak like that.