Sorry 'bout the double-post, but I've just thought:
HTTP or web proxies will not work - what you need is a UK based proxy server that supports SOCKS. You're quite unlikely to find one, I'm afraid, especially one that will allow you to transfer the amount of data that you'd need to watch streaming video.
A better, and more practical solution is if you have a friend based in the UK who is willing to install a proxy server and open up the proxy port in their firewall and/or router. You would use SSH, which is completely encrpyted, and passphrase or digital certificate protected, so you and they wouldn't have to worry about being hacked through it, or anything. They would need to be a cable or ADSL subscriber with a solid upload speed, as their upload speed limit will become your download speed.
This is basically a variation of setting up a VPN so that you can surf the 'net securely from internet cafes etc - you're basically using the cafe's (or wherever's) connection to connect to your home PC (or a UK friend, in your case), which is actually fetching the data from the 'net, and then sending the data (encrypted) back to you at the cafe (or wherever).