There might be a way to corroborate some of that, but it can never happen. Crump sent Martin's phone to his own analyst to look at data on the phone. I do not believe he is has revealed specifically who got that phone yet. Then, the phone went to MOM. All the information was on the phone. Except for GPS logs the day of the shooting. GPS logs for the days before were there. Withe that information, GPS logs from Zimmerman's phone and Martin's could have given us a walkthrough of who went where. Without Martin's GPS logs, we'll never know. Had this situation been reversed, there may have been race riots by now. But Martin supporters have suspended logic on this matter and simply don't care.
The only thing the GPS logs would prove would be where Trayvon was prior to the shooting.
It wouldn't do anything to prove what he was doing at those locations and why he was there, much less whether George was attempting to forcibly detain him with a gun.
I doubt we're ever going to get something combining both sets of GPS that shows two blips chasing each other around RTL like the Road Runner and Wile E. Coyote in the mines in that classic cartoon.
Heck, I don't think we'll even get "little Trayvon goes home from the 7-11" laid out in dotted lines all over RTL-- like one of those inevitable "Family Circus" Sunday pages Bil Keane resorted to, oh, about once every six weeks (along with "little Billy taking over the strip for Dad", and the latest "more disturbing than touching" manifestations of ghostly relatives hovering or "Ida Know" framing the kids yet again.)