Polished app has promise
You dont really need a friend with an iPhone to use this, since there is a web based map for tracking people, but the app only shines in an iPhone to iPhone exchange. I can see myself using this when Im heading somewhere to pick up my wife, or shes reading somewhere to pick me up.
Two suggestions for the developers:
1] Dont kick me out of the app to text, let me send a message through the amigo instead.
2] Give me the option to request directions to the persons dot, preferably displayed within the app itself.
Otherwise keep it simple, and focus on the iPhone to iPhone features.
striatic about
Friend Mapper