thanks friends !I don't quite understand your question. What is it exactly that you want to know? If you mean connecting the USB modem to your Air and using it to browse on the iPad and iPhone, then yes, it can be done easily. You just have to make you Air a Wifi hotspot.
How to make the Air a hotspot: http://www.askdavetaylor.com/how_to_turn_macbook_into_wireless_hotel_wifi_hotspot.html
Google and you should be able to find plenty of results. Hope that answers your question
Airtel have mobile hotspots? they can handle five devices, with vonage in the i phone and wifi can call use and india one flat fee!You'll be needing a phone too right? If you get a local card, use their [Airtel or Voda] 3g and wifi hot spot. Airtel is about 750/- for 5gb, and 1250/- for 12.5gb. Not too expensive I think, as long as you dont want to download movies etc.
mac air with air tell 3 g usb modem speed 5mb !you are mixing up two different things! as far as a usb stick is concerned the tata photon is the best. when deepak mentioned a 'mobile hotspot', i think he meant taking a 3g data plan on the sim card and then wifi tether it to your mac or ipad for browsing. but as discussed above, a 3g connection though substantially faster would enforce a data cap, which based on your browsing needs can get exhausted very quickly.
in short, 3g - fast, limited data plans
usb stick - inexpensive, unlimited data
since you would be in india just for a month, if you plan on streaming videos, i'd suggest taking the 3g route. if you plan on downloading large files however, your best bet would be the usb stick.