Show HN: WeekendHack: Does Website X Run Prestashop (and which version)

I was looking for a simple way to figure out whether an e-commerce site is running Prestashop, and if so, which version it runs. So I built : http://runprestashop.com It works by analyzing several resource files (CSS, JS) and compare them to the signatures of the different versions of Prestashop. If this is helpful, I'll probably write the same tool for Magento :) What do you think (idea, execution, etc.)? Cheers, Julien