Mobile Roaming: Cheapest Calls When You're Abroad

Hello,

There's some great information on the thread and in the article, thanks everyone, but I'm still really stuck on what would be best for me for my trip.

I'm taking in Russia, China, Vietnam, Canada, India and Australia over seven months. As well as receiving and occasionally making calls to the UK, I'd like to use my phone to make local calls while I'm in those countries.

While it would probably be best to get a global SIM, I've spent hours checking the tariffs and most seem to be really expensive for receiving and making calls to the UK in the particular countries that I'm going to - while one card may be cheap in Australia, it's expensive in China; and while another is cheap in India, it's expensive in Canada, etc. There don't seem to be any packages out there that cheaply over the whole range of countries that I'm going to.

I could buy a local SIM in every country I go to (as I'm in each long enough for this not to be too much of a hassle), but then receiving calls from the UK still seems to be very expensive (in China particularly). I just wanted to see if anyone had any advice for a good global SIM that covers all these countries? Any advice much appreciated!

Many thanks.