First of all, I probably should put something like 'gamble responsibly, it's a mugs game and you'll only end up losing in the long run', but this has to be worth a go;
888 Sport are currently doing an offer for new customers only where you can place a £20 bet and if you win, you win, if you don't win you get your £20 stake refunded. Read the T's and C's and the withdrawel policy before you deposit any money. As is usual with these sorts of sites they may want a scanned in version of some photo ID before you can withdraw money, and if you're sensible you will withdraw everything and close your account after your first bet has either been paid out or refunded.
Online betting | place your bet with 888sport the online bookmakers
All the best!
I've put my £20 on Rooney to score in both halves of the USA match at 9-1. Unlikely to happen, but not impossible and I get £200 if he does!