I have being lurking for a while and found something yesterday so i thought its time to give back!
On the http://www.threeaccessories.co.uk
website they have £50 off vouchers but you cant add them to your basket!
But i worked out how to add it, if you visit this link http://www.threeaccessories.co.uk/core.update_basket.php?task=add&product=promo2_50
it will add a £50 off voucher to your basket.
Then simply add £50 worth of gear and checkout with £50 off!!!
I would STRONGLY RECOMMEND that you buy more than £50 worth of stuff so your basket has a value of at least £5 so it doesnt look like theres loads of free orders being made!
Quite generous of 3!