that vid is alright but waay to complicated. using a drill is retarded ... drilling a tiny bottlecap is a good way to drill through your fucking finger!

this is all you need

1) plastic bottle. - 2 liter bottles work really well.
2) something to use as the bowl.
-metal pencaps... always coneshaped sometimes too small but you dont need a lot of weed with waterfalls or "flows" as we call em.
- some kind of socket
- a pipe or bowl can work
- a slider - (best way)
- NO TINFOIL!
3) a lighter
4) toilet paper or tissue

use the lighter to melt a small hole near the bottom of the bottle. just big enough to be able to block it with a fingertip.

now you can either melt a hole in the bottlecap until the plastic is gooey and shove your bowl in there to get a seal -- works well with pencaps or socket -type thing.
OR....
take your slider or similar device and wrap it in WET toilet paper.. this fits snugly over the top of the bottle. and creates a perfect seal. dont use gum for the love of god. big gross mess.

fill with water... put bowl in place. light bowl release hole . let it FLOW!!

using glass bottles is not out of the question ... my friends and i used a hammer and a nail to chip away a small hole in the bottom of various glass bottles.
ill post a vid later