SuperTrend BF

The SuperTrend overlay by Olivier Seban provides an excellent 'trailing stop' that can be used with any bar length for bullish or bearish moves. My preferred timeframe is weekly for capturing huge (Super) moves. For instance applying it to AAPL, this baby would have us reeling in a fivebagger over the course of three years. Patience and holding your nerve are key to trend following and I like to think of SuperTrend as a great big visual 'crutch' right there on the chart.
Essentially this is an average true range trailing stop, of which there are several versions available (eg see the Sylvain Vervoort version programmed by H Potter). SuperTrend differs by referring the stop back from the middle of the bar (High+Low)/2. This is similar to using the Vervoort with a tweak to the number of ATR's considered. At the end of the day its a matter of preference and what works best for you.