I guess with all the toddlers supposedly owning iPods/iPhones/iPads, this has some valid use cases. But actively supporting personal surveillance systems seems like a weird move to me after the media hubbub about the location cache.
Yes, this is something people legitimately want. There are lots of occasions where I will go somewhere with friends/spouse and want to wander but occasionally sync up or know where someone else is. It sure beats SMSing "where R U" messages back and forth.
I've got an app that does real time location sharing:
http://convoyapp.net/ aimed at people driving in groups. I wonder how well this location sharing feature will compete against it, and if it makes it obsolete?
Damn, I have never heard of glympse. I actually made my own app for this six months ago: http://l.oc8.me . Glad I'm not going to spend time creating native versions, and can move on to my next pet project. :)