Augie,
I track RSI(4) on various indices and use that signal as part of my "system".
I've backtested low and high RSI(3) through RSI(8) on various indices and common equities.
I've found that this strategy (the strategy being to buy when RSI(4) gets below 20 or whatever, and then selling when RSI(4) recovers to 40 or whatever) is unreliable with single equities. Might be able to use it with a large, diversified company like JNJ, MMM and maybe even IBM or MSFT.
As VTO report suggests, you can get decent returns on QQQ or SOX, or NYSE composite. For some reason, I cannot come up with anything feasible for OSX or the gold indices.