Get a Hefty Trash bag and some duct tape and an empty tube from your ordinary paper towel, its that cylindrical tube in the middle of roll of paper towel...now, take the trash bag, close the mouth by pulling the strings on the side of the bag but before you close it insert the tube halfway out, now, use the duct tape and tape around the bag and the tube so it would be air tight...then, viola!

This contraption is great when you have alot of people to smoke out with...use the bag to blow in the smoke, when everyone is done with the joint or the bong..all that trap smoke is STILL GOOD...so u pass that bag around, inhaling and exhaling...

Its sorta like a recycler for weed smoke...I hope I'm making any sense...Im kinda high, right now!