Call India for a Penny from BT Landlines
0844 8612525 - 1p/min
08448355000 - 2p/min
08443202929 - 2.5p/min
08443003333 - 1.5p/min

Call India (or any Country) Unlimited If You Have Broadband connection there for £5.99 Per Month Only.
Vonage
http://tinyurl.com/cx63tc
Here is How it works, In Simple words
1) You get a Vonage Box and a UK landline No. (0207, 0208, 0203) assigned to it.
2) You plugin the Vonage Box to any broadband connection/router (in UK or India or anywhere)
3) You connect a normal home touchtone phone to Vonage Box. That phone becomes the Assigned Vonage UK Landline No.
4) Now, whoever calls that Assigned Vonage UK (0207, 0208, 0203) landline No, will reach the Vonage Box and the TouchTone Phone at the receving end.
5) You can use that normal touchtone phone to call any UK Landline No for unlimited time. It doesn't matter if that touchphone and Vonage Box is not in UK. It can be anywhere. All you need there is a Broadband Connection (256Kbps +). So You can Travel with you Vonage Box and stay in touch with your friends in U.K..
6) Add £2 to ur plan and call U.S. and Canada Unlimited too. If ur Bros/Cuzs/Family is scattered in UK/U.S./Canada then Its best to send this Vonage Box back home In India. Ask your family to plug it in their internet connection and thats it. You can call that Vonage landline No using your landline or mobile and they can call your landline here totally free.  Can save a lot of money in international family calls.
7) Plus Free Vonage to Vonage Calls.