This one is mainly adapted from one I found on google somewhere so I cant take full credit for it, but here are some more succinct instructions so you can make one of your own!
This is my first instructable so be gentle if I left something out or explained something unclearly.
1 beer keg (oh yes, that is Natty Lite you see!)
1 top grate (the webber replacement grill for the 18" grill worked for me, its about 14" diameter)
1 bottom grate (I used some heavy chicken wire)
1x 10", 1x 12" 3/4"ID black iron pipe nipples
1 3/4" elbow
1 3/4" ID pipe bracket + hardware
1 3/4” ball valve
6 1.5” 5/16" bolts, w/ nuts and lock washers - used to hold up the top grate
1 bag of hardwood lump charcoal
A few chunks of hardwood of your choice (Jack Daniels oak barrel wood chips is the way to go!)
Angle grinder with cutting wheel (get some extras in case your cutting wheel breaks)
Flathead screw driver
Drill with bits
A permanent marker
Pocket knife (probably not completely necessary, but I always end up needing one)
JB Weld (for the chimney, and bottom seals, and where you accidentally cut where you shouldnt have)
All of the materials (not including the keg) were around 40 bucks.