So, you're far away from your smoker and can read the temps but can't do anything about it? I don't get it. You can certainly build your own by looking at the DIY thread but when it's finally built the cost of the materials and your time will greatly exceed the cost of a Stoker.
I've coached many on this forum who have problems figuring out how to configure their own home network such that the Stoker is visible from a public IP address. If I take the time that I've spent doing this at my hourly rate I could probably buy a stoker for each event I cook in.
Just saying.... your time is worth something. If you can figure out how to expose a web server on your internal home network running on a wireless host then you've got the network/internet part of it figured out and can use a Stoker to do what you need.
If you need a stoker like device and don't want to buy it then you've got to know a little about compilers, probably ANSI C or .NET coding, how to read schematics and know at least what a "project box" is.
OK, all that said, if you know all these things and have some time on your hands you could probably get away with all this for under $100 using an Arduino/NetDuino, a WiFi sheild, a couple of spare thermos, some off-the shelf components and brick power supply... and of course a few hours of time to code, build and debug your application.
I'm not saying it can't be done but what's your time worth?
-rob
-rob