You make it sound like one of us opened your bonnet one night and stuck it on there just to confuse you!
It's a breather pipe to the intake manifold. If you look at your engine you'll see the little mouth where it attaches. Most people when replacing the intake pipe put a little breather filter on it like this (my old setup):
Either stick a mini-filter on it, or hook it up to your new intake pipe. Don't leave it open to the elements
If you can't dazzle them with dexterity, baffle them with bull...
Nah, the corrogated one is pretty nasty. Likes to split. Check out Ben's pics half way down page for some ideas: http://ftoaustralia.com/v3/viewtopic.php?f=21&t=21743 I went for a 90deg 3" silicone pipe>MAF>MAF adapter>90deg 3" Metal pipe>Filter.