Using RSI the right way?

What RSI time frame do you use for daytrade to predict intraday overbought/oversold? I've heard a lot of money has been lost because people are using it the wrong way. Thanks!

 

"A variation called Cutler's RSI is based on a simple moving average of U and D,[2] instead of the exponential average above. Cutler had found that since Wilder used an exponential moving average to calculate RSI, the value of Wilder's RSI depended upon where in the data file his calculations started. Cutler termed this Data Length Dependency. "

http://en.wikipedia.org/wiki/Relative_Strength_Index#Cutler.27s_RSI

 

Should you shy away from buying if the RSI is over 70 or it's an indicator of a strong trend?

 

1) ?.... ??.... ! ......January 24th?....! :eek:
2) Same answer as before, use a 1-period interval.