In other words does ZoneTag send only the portion of the photo that wasn't yet transmitted when mobile connectivity is lost and regained or does it send the whole photo? It would be cool if it does but somehow I doubt it. My prediction/hope :-) is that Shozu will add this "auto geo tagging based on cell tower" feature really soon now!
From ZoneTag Photos.:
My photo isn't showing up on Flickr!
That sucks. ZoneTag may have problems contacting the server to upload your photo if you move into a weak cell signal spot. If ZoneTag is unable to complete the upload after several attempts, the photo will be placed into a queue and be uploaded the next time you upload a photo. If your photo was successfully uploaded to Flickr, the photo filename in your phone's image gallery will be prepended with "ZT".