noticed this earlier and ordered me one, ok technically it isn't free there is a £4.95 P&P charge but the dongle itself is free.
all you have to do is create an account with them http://www.3dongle4free.co.uk
and they will confirm your email address and password they will also send you a code to get the dongle for free.
don't believe check for yourself!!!
transfer a number in and get £10 free