Studies have related extensive exposure to aluminum with Alzheimer's disease. Though not conclusive, it is thought that smoking tin/aluminum foil may increase the chances of developing the disease later in life. Never, ever smoke tin foil... please. Some advice from a fiend.

Also, the aluminum can thing does not sit well with me, or the educated. There is no conclusiveness to the ongoing debate regarding the effects of smoking from a can, but as my momma used to say, 'better safe than sorry'

Yea the guy above me pretty much covered it though. Just unscrew it from the bottom of a sink tap, or faucet. Or go to a headshop and ask for a bunch of screens. Or you can tear off a nice sized nug and shove that in the hole of the pipe, creating a smokable screen (doesn't work if the hole is big).

Peace.