I do this too often.
So I want to build an Ugly Drum Smoker. Why? So I can cook pulled pork and BBQ chicken the way it's done by the pros. Also, maybe make some smoked salmon. But something that big wouldn't get used that often, so maybe I should just make a small smoker in a flower pot.
For the flower pot's burner, I'd have to get a rheostat (expensive) or a stove-top-control-the-technical-name-of-I-don't-remember (cheap, but not very precise). But I'm the hacker born! Why not use a K-type thermocouple and an SSR and control the temperature precisely from a laptop. I already have the thermocouple and can get readings from my DMM. But plugging a thermocouple into a computer is expensive; most people who want to do it need 0.1 C precession and 24/7 reliability, so one channel over USB is about 60 $.
(On a side note, why is it that a thermometer that has an LCD output is cheap, but one that would send the temperature over USB or RS-232 so expensive? I've often dreamed of a universal 8-segment to computer converter.)
Ideally, would build a thermocouple interface with this PCB, a few parts and an Arduino board. Total of about 100$, but I get 4 ports so I could log ambiant temperature and meat temperature plus a few digitals output to control the SSR. I'd also get to play with an Arduino. However, it means I have to give up some of my precious Copious Spare Time.
But if I just wanted to save time, I could use a PIB controller, about 80 $ on eBay. No wasted time, but no computer logging and meat temp would have to be verified by eye on the DMM.
But wait a second! ALL I WANTED TO DO WAS COOK CHICKEN!