I love GPS, and I love Google Maps, and I'm the first to think that there could be more done with location-based services in Singapore. (Aside: Some day I'll do my own Google Maps mashup to find out where I can take my recycling. In the meantime, I managed to get the number of the local karang guni man.) I like the idea of using something as non-geographical as the Internet to promote hyperlocal things, such as figuring out restaurants near you and the like, and I like the idea that my phone can help me do that.
But even so, I don't get Foursquare or Google Buzz for Mobile, which I played around with for a while. Via sparklette, I found "Please Rob Me", which figures out who's not at home using foursquare. (Technically, since it tells you where people aren't, not where they are, it should be "please burglarise me", but I guess that's not as catchy a name.) It may be facetious, but it helps make a good point - why do you want to broadcast your location? I get that people exchange privacy for services a lot - Gmail etc. - but what exactly is one getting in return for telling people where you are? The odd chance that a friend might be serendipitously nearby and come over and say hi?