Richard,
sorry - missed the acrimonious thread (sounds like I was wise to)... I was suggesting that when you'd mastered the art of trading, the last thing you need to do is look at something that seems to support the 'random walk' idea, as undermining your own confidence in your ability to make sense from a price chart wouldn't be the brightest thing to be doing to yourself....
On the other hand, a few folk on here could do worse that start bolting bits of meccano together and sourcing suppliers of paper rolls....