Some people use a combination of links2rss.com and feedlisting.com to create lots of backlinks. What link2rss does is create a feed from custom urls you give yourself. Feedlisting lists these and indexes them very fast (I've had them indexed almost immediatly). Now, since a few days, I've been getting the error "Invalid rss feed url please correct the problem: Sorry, but auto feed generators are not allowed." whenever I submitted one. There's one really simple solution to this: bit.ly. Just copy the feed URL and make it a smaller link through bit.ly or any other service. Now submit the feed to feedlisting, and it will work again.