Is geolocation interesting information? Have you ever wanted to geolocate a blog? BlewSpace is a new Google Maps mashup which aims geolocating every blog out there. It might not be considered geolocation but georegistration, but in the end there's a map full of blogs so you can place yours. You can register your blogs for people to locate it. You can also categorize it, and even ping it (so I can't register other people blogs and say it's about crap).
It's still in early beta (2.0 fashion ;) ), and there's an interesting wishlist you can increase.
From a commercial point of view I think BlewSpace has some interesting potential, specially for bloggers meeting arrangement. When BlewSpace activates spatial querying you could list the blogs at your city, for example.
Geolocation makes Web 2.0 communities more tangible. They're not only groups of virtual avatars, but actual people, some of them living next to you.