Location-Based Social Networking: A fad or here to stay?

I just read this article comparing Facebook Places to Four Square and it got me thinking...is location-based social networking a fad or is it here to stay?

After seeing the comparisons, it seems that from a business model perspective, Four Square is better equipped to provide value to businesses and therefore monetize this aspect of the application. Facebook Places appears to have more of a social aspect to it and I really don't see it taking off. At some point, I feel people are going to get over this notion of ensuring your friends know where you are at all times. I mean, if they really want to know, they can send you a text message, right?

Certainly, there is some value in the Four Square's ability to provide discounts, but I still have trouble seeing location-based marketing products like this really taking off. What do you think?