If like me you aren't too keen to attach a big mudguard to your bike but still want to arrive at your destination with a dry bum then you might be in the market for an Ass Saver. It sounds like someone who helps you out ("Thanks for that Jeff, you're a real ass saver!") but it's actually a small folding mudguard made from (mostly recycled) thin, foldable plastic.
"The SmartAss fits nicely onto the rails of your saddle without any tools or fittings. When it stops raining, simply fold it up and store it underneath your saddle until next time. The SmartAss fits about 80% of all standard rail saddles"
This video shows how it works:
