I was planning to buy Tata Photon usb modem, but then I came across timewasteblog.com/2010/12/17/unlocked-best-cheap-3g-data-card-bsnl-airtel-reliance/and then I shifted my focus to getting an unlocked usb modem. Just today I read that Airtel will launch 4g in Delhi. So it makes sense to invest in a 4G modem. Can anyone recommend a good 4G usb modem which will also work with a 3G sim.Thanks