Incidentally, http://vegasclick.com/gambling/bettingsystems.html is a very nice explanation of betting systems and why they can work in the short term. Apologies if it's been posted before in this thread, but I didn't see it.

Also, in case I sounded too negative before, I do plan on giving it a go again. It's fun (betting over three hundred quid ($600) on one hand of blackjack was quite an adrenaline rush for a simple working class lad like myself) and if you combine a betting system with a stop-loss and a bit of bonus whoring then you have a fair chance of making cash off of it. Like I said, I'm still £400 up for a few hours 'work'.

Betting arbitrage seems far more interesting, but you do need a hefty bankroll to start with that.