It's for when you are going gonzo!

One of the reasons mtbs will never look as good as road bikes.

Still laughing at that one and read the post 5 mins ago.....lol.

PMSL.

I had one of those Crud front fender thingies for a wet week in Morzine (is it ever sunny there?) and it wobbled a bit, scuffing the crown.  Then I had a tumble on the second day or something.  The nylon straps holding it on snapped and I binned it then fitted a bit of old inner tube, which worked just fine.  This looks a bit more durable, but they probably need to make a few different lengths to fit different bikes - won't really work on a long head tube bike...  Or just get one of those THE front fenders (here), they work great apart from scuffing the underside of the steerer.