Instructions:Free voucher code is 5F0P1NJRY (3rd digit is zero not an "O")
Wager £25 on any event - Grand National, football etc etc. Win or lose and Betfair will recredit your account with another £25! Betfair are looking to expand their customer base, so have a look at this excellent deal.
Go to Betfair.com and open an account. It worked for me and only took a five minutes. You do need a credit card.