Hi, first post, building a couple of projects using the Duemilanove. All a bit new to me, I last built control systems with relays and contactors in 197*! Still, it's all electrickery..
Happy to welcome you into the forum 
Have fun with arduino 
Hey Mike!
Got my own start in the late 70s with relay racks and such. Welcome to Arduino! I've had a lot of fun, I'm sure you will too!
PLCs and ladder logic?