mpicpp sends news that Uber is renewing its push for a patent on "surge pricing," the practice of increasing rider fees when many people are trying to find transportation. The system measures supply (Uber drivers) and demand (passengers hailing rides with smartphones), and prices fares accordingly. It’s one of at least 13 U.S. patent applications filed by Uber or its founders to give it an edge over potential rivals ahead of a potential initial public offering. So far, Uber hasn’t had any luck. Ten applications were initially rejected by the U.S. Patent and Trademark Office for “obviousness” or for covering something not eligible for protection.