Well, I just used that
http://proxy.virtual-browser.com/ to access xlned.com and this time it gave me the option for the free week.
I guess I'll try in a week and see how it goes, after I'm done using my current account.
Actually... it's quite wierd at the moment. I'm at work, which has the same ISP as my house, and going through proxy.org at the moment is giving me the option I was looking for.
I wonder why it wasn't showing up earlier. Guess I'll try again when I get home and see what's going on.