iPhone Hacks has a really cool article about
Sekai Camera - an app made by a Japanese company.
Here's a YouTube sample of the app:
Cool huh? Well, the iPhone Hacks article says it really doesn't use much information from the camera but more from GPS/cell towers.
Would you buy it for a premium price of $9.99?
I suppose the usefulness of this app would depend on how many people in your area actually post reviews and things like that.