Excellent thread! keep it up!!
I consider the trendline analysis as THE MOST IMPORTANT TOOL for a technical trader because technical analysis is built on the assumption that prices trend.
To be a successful trader, you have to use a method that gives you a statistical edge. This edge comes from the tendency of prices to trend. In the long term you can make money only by trading in synch with these trends. Thus, when prices are trending up, you should only buy. When prices are trending down, you should only sell.
So using trendline analysis one can easily identify the trend! The trend can either be up, down or sideways as illustrated by the many examples in this thread.
When you trade in the direction of a trend, you are truly following the markets rather than predicting them. Keep in mind that most unsuccessful traders spend their entire careers looking for better ways to predict the markets.
You can brush up on your trendline analysis with this short tutorial at
http://stockcharts.com/school/doku.php?id=chart_school:chart_analysis:trend_lines
Keep posting your charts with your analysis. Interacting and discussing your views on trendline analysis is one great way to learn!