I use Hotspot Shield, too, from Anchor Free (
http://www.anchorfree.com/). I've not tried HBO on it, though, but Netflix, Hulu and all the basic and basic cable network sites I've tried work on it. I did have trouble with it in our old place, where the broadband just wasn't fast enough, but it works fine where we are now.
FYI - you can use your US netflix account in the UK. Or at least you could as of a couple months ago. The downer is that you only get the UK content, which is not as extensive as the US.
You still can. I use my Netflix account daily. I never switched it over from my US account, because I have so much history on it, and like its recommendations based on my thousands of reviews, and they apparently can't maintain that history while changing your country of payment. Or at least, they couldn't back in May when I tried. It's not much bother to send the $9 over to my US account each month, so I just do it that way. And if I want to stream something that's only available in the US, I just use the Hotspot Shield, and it works wonderfully.