I'd like an app that would take my gps position and email (or text) a link to google maps with my location marked so that anyone with a smartphone (android, iphone, blackberry, etc) could find me. Is there an app that does this?
And yes, it's built in to google maps.
Tap on your location, you'll get a info bubble, tap that, then select "send location to others"
It's called Latitude.
It's included with my Incredible as a separate application but you can also get their from Maps (menu->Latitude).