2G/3G SIMs for Phone/ Data for iPhone,Laptop & iPad in Bombay Bangalore & Nationwide?

I have the following scenario:


iPhone 4 - GPRS/Edge Connection - 2GB for 99/- Data Plan with Vodafone Postpaid
Thinkpad Laptop w Win 7 x 64 bit - TataPhoton Plus for when out of the office/home

The last time I checked 3G data was a bit over expensive. But I need to look into it again.

Are the Data plans available on 3G for USB sticks equal to or more expensive than Photon Plus etc?

Also, I am considering getting an iPad 3 soon from Singapore or Hongkong.

Now I am aware that iPhone (and its Data Plan) can be used for tethering over USB & Bluetooth (for my Laptop) and also as WiFi Hotspot (for Laptop & upcoming iPad 3).


My base for now is primarily Bombay and have frequent visits to Bangalore & outskirts. Occassional travel outside across country (not frequent).



I did consider getting different combinations of the following:
- 3G-USB Stick (Huawei etc) types
- MiFi type (3G/ EVDO) WiFi Router

But before I do so I was thinking WHY BOTHER?

Location and more about Second number? :

Is there any SIM card that will not have EXTRA/ ROAMING charges (Phone and/ or Data) between Bombay and Bangalore? Would MTNL be a suitable second SIM Card?

When I frequent Bangalore I want to maybe minimize my Roaming usage on Bombay Vodafone number. I am thinking of getting a suitable second SIM card with Bangalore number for this?

Data Usage - Acrosss Devices & Locations:

Now, my usage at home/ office is taken care of by the home DSL connection & home WiFi Router for all the devices: iPhone, Laptop & future iPad

The thing is when I am travelling or out of the house, I dont see it making sense to PAY for individual connections for each of the devices.

I never step out without the iPhone so its always with me.

The other devices that I may use on the road when needed (Laptop/ iPad) could use the connection of iPhone via Tethering or Hotspot.

I am wondering if I could just get a GOOD DATA Plan on 3G Data (with my original Vodafone SIM or a second Bangalore SIM) and not have to bother with the above stuff.. the 3G stick, 3G/EVDO Router and even eliminate my Tata Photon Plus?