I have an idea for an iPhone app, alas I don't know anything about app development so I can't turn the idea into a product.  Somebody should take this idea and turn it into an app...if you do drop me a line and I'll buy it.

So the general idea is an app that uses GPS coordinates to manage call forwarding and ringtone selection.  When I'm at home, I like to leave my phone on my desk, or hooked up to my stereo to listen to Pandora.  It would be very useful to me if I could automatically have my calls forwarded to my home phone when my phone is within XX feet of my home GPS coordinates.  Also, it'd be nice if I could enable/disable certain ringtones when I'm at work or at a client's office.  I envision this working by allowing you to select a default ringtone which would be used when you're within XX feet of GPS coordinates you've marked as 'work' or 'client office', and then you'd select another ringtone as a default which would be used when you're everywhere else.  The idea behind this should be obvious, but in case it isn't, I'd like to be able to have whatever ringtone I want selected as a "not at work" default, and a more professional ringtone when I'm at work so if my phone goes off in a meeting it isn't going to play a RATM ringtone.

The options I envision the app having are an update frequency (in minutes, 1, 2, 5, 10, etc), radius in feet from the GPS coords to match (i.e. 100' from coords XX should forward calls to phone number xxx-xxx-xxxx).