My TradeSpotting system is also effective to use on 30 minute Forex charts. I have posted a 30 min chart of the EUR/USD from the 8/9/2011. This momentum move occurred during the US session and yielded up to 160 pips. Unfortunately, for us down here in Aussie land, many moves do occur during either the London or US session.
So, for those of you in the US trading zone, 30 min chart trading using a trend trading system, such as TradeSpotting, can be an effective form of trading.
NB: explanation of the blue rectangular boxes. These boxes illustrate different trading zones. The left hand side of the blue rectangle denotes the Asian session, the right hand side denotes the London session. The un-shaded section represents the US session.