The electronic bits:
2 x 1051 USB Temperature Sensors $57 each
1 x 1018 USB 8/8/8 I/O boards $76
2 x UEIATT50 K-Type liquid probes $36 each
5 x switchtails $15 each, I'm only using two right now
(from SparkFun Electronics)
1 x 18-pin wire-wrap socket $2
1 x ULN2803 DIP 8-Channel Darlington Driver $2
(From valves4projects on ebay)
2 x 1/2" Solenoid Valve 120-Volt AC VITON STAINLESS S21V $41 each
I also made a heat-stick after reading about them here on homebrewtalk... I have parts for two more but I'm only using one at the moment.
Also: 2 x GFCI units from Home Depot for circuits that don't have 'em, and those heat-sticks are wired for GFCI. Don't want to electrocute myself, thanks!
I got my three Eastman 7.5 gallon turkey fryers when someone was blowing them out for $80 each... I drilled holes in 'em and put in weldless bulkheads and valves a while back... so I needed solenoids that fit the those 1/2 inch NPT bulkheads you see on homebrew supply sites everywhere.
1 x laptop running linux, apt-get install pygame, download and compile the Phidgets C Library 2.1
1 x dangerbeer autobrew python program (a work in progress) written by yours truly.