I'm sure most of you have found this by now, but I'm a bit slow.
http://www.ippf.org/It's Planned Parenthood's international site, which isn't anything new, but what I never noticed is that they have a Directory of Hormonal Contraceptives. So you can look up the one you're on in the US, look up other brands with the same composition, and then look up what brands are available in other countries.
I used to be on TriLevlen in the US and liked it quite a bit, so I looked it up, printed out the other brands with the same composition, then compared that list to available brands in the UK and now I have two potential ones to ask my GP for. I find that GPs don't know much about BC and it's good to be proactive about it. I've been on Depo for a year and really like it, but I'm not married to it and don't want to stay on it indefinitely because of the bone loss issue. I'd always figured if I could find a pill in the UK that I liked as much as TriLevlen I's be happy enough to go back to the pill. And now I can!