O2, one of the biggest U.K. Cell phone networks, has realized that it can seize a place in the digital payment revolution by launching its own system...the O2 Wallet. It's a digital charge card system, which you fill up via payments from a traditional credit card, and then you can transfer funds between £1 and £500 between phones and to the websites of over 100 big-name retailers. For now it can't work in stores, but showing the counter-cultural powers of mobile pay the app lets you scan the barcode of an item you like in a store, and then helps you find it cheaper online. Plus NFC capabilities will be added soon to allow in-store purchases. It's clever, and is a taster of bigger things to come, but it's also a demo of how muddied the mobile payment waters are becoming as every enterprise in the race, from operators to phone makers to credit card firms tries to jockey for best position.