Went to South Africa to visit my parents for christmas and found out a nifty thing about t-mobile. If your abroad (anywhere in the world) and you send a pic message (to anywhere in the world) it costs 20p and is INCLUDED in your allowance - it used to be excluded of your allowance. i know this works on their flex packages, but not sure about any of their others.
Means you can send up to 1000 characters & a picture/video clip (up to about 15) seconds for next to nothing! On the other side, 1 regular txt message costs 40p!
Hope it helps!