Seems some B.A.R.F. folks don't anything get in their way. Here are some epic adventures from barf'er "Luckette". Links below:
Epic Ride I
These posts are filled with some great photos and videos of slick tire riding through things that you should have a set of knobbies for.
This is an old video, but I thought I might share it if you haven't seen it. It's called "One Got Fat" and it's an old-school bicycle safety video. Kids with creepy monkey masks on bikes - what more could you ask for?