first of all - that would be not possible with a regular phone - there are some hacked phones "in the wild" - but that is something different.
a a normal gps device would not send anything to a satellite - that would use a huge amount of power compared to the "regular" was - it sends the coordinates via gprs to a server
despite the fact that a phone is switched off - it's not switched off
the network could always track them if they are in the range of the network. ever layed a switched off phone beside a clock radio ??
funny sound in the middle of the night - that happend when the switched off phone and the base transmitter station communicates
BUT - the network didn't collect those data - to store that amount of garbage data would become huge - and normally none needs that.
aned even if the would store that kind of data - the "regular joe" would never get his hand on that data
(since i've worked for 2 yrs at o2 i know a little bit of that stuff)