One of the best and cheapest Friday nights out is a trip down to the Wimbledon dogs. You can usually find a deal online where you get entrance, a beer, and a bet for around £10 and best to go with a group. Each race is only 30 seconds long and with 10 races in the night there is plenty of opportunity to win or lose. Although I know nothing about dog racing and was going mainly by the name (such a girl thing). You can bet a 1-2 reverse (you choose the 1st and 2nd place dog and they can win in either order) or go for tri casts (the pooches finish in the predicted order). Tip to a good night: bet cheap, drink hard, and yell loudly.
Wimbledon Greyhound Stadium, Plough Lane Wimbledon, London SW17 0BL