iPhone 3G GPS is unreliable; seems to use assisted-gps only A few months ago the GPS in my 3G has become really unreliable.  The blue circle in google maps looks to be about 2 miles in diameter, and never shrinks to a pinpoint.  Apps like RunKeeper can never get a strong enough GPS signal.  This may have coincided with the iPhone not picking up wifi unless almost on top of the access point, but that could have been a coincidence.

Things I've tried that haven't worked:


Trying to lock on to a satillite when outside with clear skys for >30 minutes
General Settings -> Network -> Cellular Data -> Reset Settings
Restoring the iPhone from a back-up
Giving the phone a prelonged stern look


Any ideas greatly appreciated.
The prelonged stern look didn't work??? Lol 

I see that you tried restoring from a backup. Try restoring to stock software instead of your saved backup and see how it works. I've noticed that sometimes erratic behavior is caused by corrupted files within the actual backup image.

If that doesn't work, try taking it in for service...I really don't think that's necessary though.

Hope this helps!