My god, there is such a lack of understanding of GPS, A-GPS (assisted GPS) and "other" positioning systems by use of triangulation of cell towers or wifi spots.
Firstly the iPhone (and iTouch using a db of wifi spots) can roughly locate your position using a triangulation of signals from cell towers, which in itself is quite a bit of funky technology. This is *NOT* GPS in any form, assisted or otherwise.
Secondly, the iPhone 3G has a full blown GPS chipset in it, so can get your position down to a few meters. But, like all GPS units it has to download all the ephemeris data from the satellites. This can take up to 10 mins for a unit that has no knowledge of its position at all.
A-GPS is superior to plain old GPS and don't confuse it with other things. That makes Greg the owner of the
This is where *assisted* GPS come in. It connects to the interweb and downloads all of the satellite data from a server somewhere at web speed not at 50 BITS/sec that it takes from the sat itself. Now, equipped with all that data, you get a fix very quickly.
That makes Greg the owner of the stupidest comment here.....