TechCrunch looks at Nrme, a soon to be released only for the iPhone app. The big deal? You only received messages from those within 9 blocks (no idea how that's determined). There's no following like Twitter and idea is to get information about what's in walking distance in a city say, or in a constrained environment like a concert venue or large conference center (think about San Deigo's for example...)

Again I note, this is a feature I'd like to have with my messaging tool of choice. I don't want a special app to provide that feature. I don't expect this to take off, rather, I expect other providers or third party developers to add in this same sort of tool.