Hola Unblocker is a really cool add on for Firefox and Chrome that lets you trick websites into thinking you're in the UK (or any other country for that matter).  I've been using it with BBC IPlayer and have been really impressed with it.  I've been able to stream from my laptop without any problems.  It should also work with ITV Player, Channel 4oD and Channel 5's Demand 5.

I still have a VPN with HideIPVPN to be on the safe side though, which I use on my Android IPTV box for IPlayer etc.

Here is the Firefox Hola Unblocker add on:

https://addons.mozilla.org/en-US/firefox/addon/hola/

You can get Hola Unblocker from the Chrome Web Store here:

https://chrome.google.com/webstore/detail/hola-unblocker/gkojfkhlekighikafcpjkiklfbnlmeio