Easy Apple pipe:

Take an apple. Core it, as you usually would. Now, you should have an apple with a big hole through it. Now, use the corer to make another hole that intersects the first one at a 90 degree angle. DO NOT GO ALL THE WAY THROUGH THE APPLE. You should now have one big hole going all the way through the apple, and one hole that intersects the first one, and goes half way through.

Now, make a tin foil "bowl" in the hole that doesn't go all the way through. Using a pen/needle/whatever, poke a couple small holes in the tin foil. Fill the tin foil bowl with some dank greeen, hold the apple so the bowl points up and your hand is covering one end of the long hole, light the green, and suck. To clear the "chamber", let your hand off of the hole opposite that on which you're sucking.

Voila, nature's own steamroller!