Time-rich, cash-poor? Simply crack the lottery scratchcards!
If you could pick somebody to be your new best friend, you'd probably want Mohan Srivastava. Who hell he? He's a geological statistician from Toronto, and he found he was able to crack lottery scratchcards and accurately predict whether or not it'd have a prize.
According to Wired, Srivastava started looking for patterns once he realised that since scratchcards are mass-produced and there are only a finite number of prizes, their printing can't be random; it has to appear random to the ordinary consumer, but there has to be some algorithm at work to produce the effect.
The cards he initially studied were slightly different to the ones routinely seen in UK stores, since the market is more advanced in the US and Canada. These scratchcards used a noughts and crosses board with visible numbers printed in each square; a hidden scratch-panel contained the player's numbers and a player won if any combination of their numbers were found in a row printed on the board.
Each playing card contained eight noughts and crosses boards - Srivastava studied several cards and noticed that if a number was only printed once on the boards, then it was very likely to be one of the player's numbers hidden under the panel.
When Srivastava tried to report the issue to the lottery authorities, nobody responded - they simply assumed he was a mad man. It wasn't until he sent a package of unscratched cards divided into winners and losers that anybody took notice.
That was in 2003. According to Srivastava, there are still scratchcards being issued with similar flaws. There's also enough anecdotal evidence to suggest that organised crime may be exploiting the flaws in order to launder money. The reason the problem still exists, eight years after Srivastava first discovered the issue, is that everyone involved in the lotteries believes them to be impossible to crack.
Admittedly, Srivastava is a trained statistician with degrees from MIT and Stanford, and UK scratchcards don't tend to reveal unique information in a similar way, but if you've got time on your hands you can probably be a millionaire before the 5 o'clock whistle, eh? Off to the newsagents with you, then.