I've never been a big fan of GPSGate (
http://www.franson.com) but their latest version for PPC is very, very cool. The program originally was designed to share a GPS connection between apps, and now WM5 does that without any extra software. So Franson had to come up with something new.
With the new version I can send my GPS location over my Sprint connection (updated every 30 seconds I think) and anyone I've told can see my location on Google maps on their computer or on another PDA. With these storms we've been having in the midwest it would actually be helpful (and not just cool). As long as the little blip on the map keeps moving I guess everyone would know you're okay!
Anyway, there's a free trial and it's worth checking out. - sheureka