A slightly higher class home-made gravity bong than those made from two-liter coke bottles or milk jugs (yes, I have smoked out of a milk jug ... dammit, I was fifteen!).

Materials needed:

    One Sobe bottle
    One sobe cap two of both cap and bottle isn't a bad idea, just in case of mistakes
    a hammer (smallish is better)
    a small screwdriver
    either a pre-existing bowl or one made of your own devices

To Make:
    Take your bottle over a sink or a garbage can. Find a spot near the bottom of the bottle (where the bottle goes back out and is a little textured). GENTLY take your screwdriver and hammer it (again, gently, or you'll break the bottle), creating a small hole for the carb. Be sure not to make this too small, or the bong will be useless.

    Take the cap and use the same screwdriver and hammer combination to provide a hole in the cap to put a bowl in (premade glass stems from bongs have worked best for people I know).

    If you don't have a bowl and you're really jonzing, you can punch a bunch of small-ish holes (best to use a little nail/pushpin, but an earring will work in a pinch) in the cap, indenting the area where the holes are slightly so that nothing has a chance fall off. Now you have a psuedo-screen. Just BE CAREFUL

    Fill the bottle with water, preloading the bowl and having a friend hold it for you. Screw the cap on the top of the bottle with the bowl on top. As you let out the water, light the bowl and let the water do its magic.

Strangely, this seems to work better than most gravity bongs according to all who have tried it. Also, obviously the glass hit tastes better than one out of plastic, so another semi-obvious benefit is clear.

Does this make me a certified bong technician, or what?

Incidentally, for those confused, this purpose of a Sobe bong is to smoke tobacco out of (and, of course, only for those who are 18 or older, at least in the U.S.). Using it for any other purpose would clearly be illegal.