This Instructable covers how I made a Smoker (for smoking meats) from an old office filing cabinet. The end result is a smoker that has a drawer for the fire, and a couple drawers for meat. Its a direct smoker, much like the black cylindrical metal ones you can get fairly cheap at the local hardware store, so regulating smoke and temperature takes a little practice.
Step 1: Stuff you need
Metal filing cabinet. I got mine free from work as it was old and the cloth cushion top was torn. Mine is also an under-desk sized one, though this should work for the full-height ones as well (Tower of smokin meat!).
3/4" Oak Veneered plywood 2'x2' (Might need larger if your cabinet is longer/deeper. Mine was 2'x1'-5")
~8' of solid oak edge moulding. I used a fairly simple astragal pattern, 1.25" (half-round top with a chamfered curve extending the bottom).
Grill grates. They make grill grates that can be extended to fit any grill. If you can't find one to the exact size you need, get these instead.
Washers, grommets, screws, nuts. Various small bits of hardware
Aircraft remover: Highly effective at removing everything down to bare metal. BE CAREFUL WITH IT, it will burn the #@$! out of you if you get so much as a drop on your skin, and removes/eats paints and plastics and just about anything not metal.
Grill/high-temp paint (Rustoleum flat black grill paint)
Shelf support pegs (metal)
Drill and bits
Thick leather gloves (tin snips leave super sharp serrated edges!)
Rubber gloves (made of stuff Aircraft remover will not eat, ie: not nitrile. Thick yellow kitchen gloves seem to work, or heavy duty PVC ones)
paint scraper (I got away with a cheap plastic set, went through 3 of them though as aircraft remover slowly softened them up into mush)
Grommet punch/press (should come with any grommet kit)
hack saw or dremmel cuttoff wheel (bolt cutters will do too)