Can you just use the email on your phone? Free, no character limit... Or skype?
Otherwise I think with most networks you have to buy a bundle and then you get much much cheaper international calls or texts. I found the guys in Carphone Warehouse on Cornmarket really helpful for advice about what's available across the networks.

I feel I should point out that not everyone has e-mail on their phone...sorry Jendelion, not trying to get at you, but sometimes I feel like standing up for luddites like me!

Yes, I don't have email on my phone either ! (But having just heard about the new 4G broadband network, I might actually upgrade to a smart phone when it reaches Oxford - sometime after Xmas). In the meantime, if anyone knows how to get free international texts ..?