I am not so clever to understand what is the usage of this site, so I cant explain it here . But I hope it can helps the others a lot
Here is the link http://convextra.com/
This is useful if you need to retrieve a list of something. Try it with ebay, you'll end up with a listing of all the products available on the page you entered. I've a friend who used something like this to download a huge list of businesses from yellow pages.
