I use 20 on a 5 min chart for intraday trading and 50 and 200 on day charts for longer term, i also think the mining indexes are very important predictors and obviously the euro and dollar index, i believe if you simply stick to the rules money can be made, the biggest killer is to large a position being held during choppy markets.
edit:the cot reports used to be amazing and i think they are coming back as great signals to buy or sell,certainly worked out in october(i think oct)
RE Bernanke,very interesting indeed.