Hello all,Having used a fixed line Broadband all my life I am new to mobile internet. I am about to purchase a laptop and will also need a mobile USB connection. I am quite confused with what is available today because I am quite out of touch with the technological changes.I don't know what is 2G,3G,GPRS,EVDO, etc. The whole thing is made further complicated by the number of providers and by the tariff structures.Can someone please point me to some link where I can begin to understand what all this means and so I may be able to make an informed decision on what USB connection to go for?If not, I will give my details here so that the person might be able to suggest the best possible option for me today.I will be living in Calcutta. Since USB internet is not so cheap, I wonder if it might be a good idea to have a nice and cheap fixed line Broadband as my primary connection and to use the USB option only when I am mobile.I would ideally like something that is preferably unlimited, fairly cheap and offers the best speed and connectivity across India.If someone can throw some light on these issues, I will much appreciate.Thanks.