So which is the best option. I would have said Google Talk (sorry not Skype, I find the quality of Skype really poor relative to Google Talk), but I would attempt to provide a phone to phone/web to phone solution, not a web to web one.

This article would edited as newer services show up, but at this time I feel the service Pennytel from Australia (can be used from any country) is the cheapest option.

Pennytel offers

• Cheap Aus $0.02 cents per minute calls to India
• Can access through their softphone by logging onto http://pennytel.com.au
• Access through Pennytel’s iPhone application, only through Wifi or through 3G network if you have iPhone is jailbreaked.
• Access through your mobile phone by using Pennytel’s own sim card (Aus $8 per month). The sim card option is available only in Australia. This is the best way if you want to make or receive calls on the go.
• Supports voip through a adapter, so you can connect your everyday phone to make voip calls.

Browse through their plans to find other features like $0.08 cents unlimited calling to USA and using it through a voip lan adapter.

Related posts:

1. Free calls to India (Mobiles to PC)