Google Latitude. If you're running an Andoird phone you can also open the Maps app, get a fix on your position, and then email/SMS a link to your location to anyone you like. That, of course, assumes that your fingers haven't been eaten by a rabid fox.
@Wilkie - I think you missed the OP's point.
No, I don't believe I have.
I have just given my opinion, which is different from the OPs.
I don't know what, in particular the OP fears, but I don't fear it and I don't like the idea of someone, anyone, tracking my movements.
That's all.