URL probing technique

With all those SEO-friendly URLs it's entertaining to see how the web application respond to misspelling/typos in different parts of the "folder hierarchy". Depending on how close misspelling to a root of the URL the application would throw something ranging from nice "article/product not found" to ugly 500 or 404 canned error page.

And that's how one can sniff what CMS and shopping carts website is made of ;-)