I haven't really kept up with the thread but I'd thought I'd say something here. I think trendlines are far less useful than regular bar and price action signals. They can definitely work their magic at times, but one of the problems is that I find they need a lot of adjustment and can't often be trusted unless there are 3 solid hits and/or the market is synched in time heading into the third hit (as in 3 hours from point one, 3 hours from point two, and approaching the area after another three hours). I will only trade off a trendline if I see the market react to it fairly aggressively. This chart I made a few months ago sums up how I feel. At the time, the point was that I used to take reactions off of pullbacks to trendlines, and as the chart shows trendlines don't often signify any change in trend and reactions to pullbacks don't necessarily mean much either. Edit: the last signal has more to do with the inside bar (which was still bearish) - haven't looked at it in a while.
Let me contradict myself though and show one that worked great. -- To this day, probably the best TL I've ever seen. Ignore the blurb, it was just something for me to remember.
I understand a good bit about trendlines, I just think they have a lot of limitations. I'll keep quiet and observe the thread for a while though since I haven't kept up with it, unless people have questions.
http://bigcharts.marketwatch.com/help/glossary/detail.asp?area=trendlines&word=0 they are pretty simple, and older than noah