[backtoreality15]

Does geotagging rely on data connectivity (EDGE/3G) to tag the picture? Or are the coordinates directly downloaded through the GPS?

The reason I'm asking is that I still want to have photos geotagged when I'm away on travel without ridiculous roaming data charges.

[delta_foxtrot2]

Depends on the phone/method of location aquasition, AGPS (assisted GPS) requires support from the network and can be charged for apparently, where as GPS is a chip in the phone getting signals from sats and calculating location that way.

In short to be sure you aren't charged disable A-GPS in the options section of the phone, and just use GPS if your phone has/supports it.