Filed under: CellphonesWho'd have thought the end of 2007 would see US cellphone carrier heavyweights duking it out with PR one-upsmanship to be open? Seriously, someone pinch us, it's as amazing as it is farcical. So the latest development in big network "openness" has USA Today running off in the opposite direction with AT&T CEO Ralph de la Vega's comments that "You can use any handset on our network you want We don't prohibit it, or even police it. We are the most open wireless company in the industry." We think the headline "AT&T flings cellphone network wide open" kind of says it all.The reality of the situation? Nothing has changed between yesterday and today, and, a