find a pen tool page/site/tutorial

Last week, we worked on the Pen Tool chapter of the book. The pen tool is a great one, but it can also be a bit frustrating. I would like each of you to get on the web, use a search engine and find a web page/site/tutorial that further discusses the Pen tool. Once you have a found a page/site/tutorial you like, go to the blog and add a comment to this entry that includes the web address of the page/site/tutorial you found.