I recently stole an idea from a cable cooking show on how to make your own smoker and damn if it didn't work!
I took a large (18" diam.) terra cotta flower pot and an equally large but shallower one for the top. I put a small electric hot plate in the big pot with the cord out the hole in the bottom. I set the pot on some spare floor tiles. The whole thing cost about a hundred bucks including the pots. You could do it for less with smaller pots.
On top of the hot plate went a small pan for wood and a Weber replacement grill rack for the meat. A meat thermometer went in the hole in the top pot to measure air temperature.
I did a dry run to adjust the hot plate to maintani about 210-220 degrees. As a trial I used a 2lb. boneless turkey breast which I brined for 36 hours. I smofed it for about four to five hours with cherry wood. For a first try it was excellent. It was a little salty but thoroughly and evenly smoked. Next I'm gonna try some salmon recipes I found. My goal is to convince the wife to let me do Thanksgiving on it if I get good enough. Worth a try and you never have to add more charcoal.