[petkow]

Peter. Forget about getting a special roaming SIM (like truphone etc.) as the rates for these for countries like India and Nepal are pathetic, and probably not very different from what Vodafone are charging you in normal roaming.

There is only one feasible economic solution:
1. Get yourself a UK DID in an area code of your choice (there are hundreds of suppliers). Make sure it allows your call to be forwarded to a SIP address. (e.g. I have one from Voiptalk that does this). You can either give your customers this number, or have your normal Vodafone number forward to this.
2. Get yourself an account with a Voip provider that has cheap calls to mobiles in india and Nepal. e.g. Voipgain does it at arround a penny a minute
3. When you get to India/Nepal or wherever get yourself a local prepaid SIM. (actually no longer as easy as it once was, but still possible provided you show ID and a local address)
4. Divert calls from your DID provider to the Voipgain SIP address (or one that gives cheap calls to India). You can do this in the settings of managing your incoming number. Also, in the Voipgain control panel, divert all incoming voice calls to the number of your prepaid SIM in India.
5. If you do not have a SIM in India, you can divert your number to a hotel, landline etc, or worst comes to worst, divert it back to your UK vodafone number. With Voipgain this only costs 3c/min, but Vodafone will obviously charge you incoming charges if receiving a call while roaming.

Sorry this is all probably a bit confusing (no time to explain properly), but I hope you get my drift. I have done the above on around 5 trips to India with no problems. I can receive calls made to a UK landline number (or my o2 mobile) in India for under a penny a minute.