If you use two mobile phones for a CDMA connection like the TATA Indicom or the Reliance, and a GSM connection like the Airtel or Vodaphone, then its time to change your phone. There are mobile phones which can have two phone connections working at the same time on a single mobile phone.

Spice Dual sim GSM CDMA Phone D88n is available in India. It has all the rich features that a basic phone needs and is costing about INR 9000.00.

This phone can give you two numbers which will be working at the same time. You do not need to switch between the connection all the time when you need to use it. Other features includes camera, 1000 numbers phone book, expandable memory upto 1 GB, Games, alarm, bluetooth and many more features

I have not used this phone, but I was looking for something like this. Does anybody know any pocket pc which can have this feature of dual sim?