The Waterfall
The waterfall is probably the least known and least effective way of smoking weed, but it's fun and a cool thing to show-off.
Making Your Own Waterfall
Take a 1 or 2L bottle and poke a hole in it towards the bottom, about the size of a nickel.
For your bowl, take the cap off and cut it through so all you really have is a loop that screws on to your bottle. Take some tinfoil and push it through the loop so you have a bowl that goes into the bottle when you screw on the cap. Poke plenty of small holes into the tinfoil at the bottom. This is where your weed will be burnt.
Now, cover the hole with your finger and fill the bottle up with water. Screw on your bowl, but make sure it doesn't get wet. Now, burn the weed and take your finger off the hole, letting the water drain out.
If you do this properly, as the water drains out it will pull the smoke from the burning weed into the bottle. Now cover the hole and inhale the smoke. Alot of work for a toke, but it looks cool.