I've used one of these ERGO saddles on and off for a few years now. Right now it's on a BMX bike, no problem pedaling standing or sitting. It takes a bit of getting used to but it's quite comfortable



Looks like it's available for as low as $15 plus S&H from Amazon vendors:
http://www.amazon.com/Ergo-Seat-Clas...3712226&sr=8-1