I would use the Plat'Home server as an irrigation controller. I have developed software to control my ranch's irrigation system (5 acres of irrigated pasture and orchard). The problem I have is the controller in the pump room is subject to California Foothills summer heat (40C and more) and, worse, ubiquitous dust. I have yet to find a server that can run reliably in this environment.
Ah yes, the Californian summer is a challenge for hardware! We haven't had much of a summer over here in Tokyo yet, but I've heard this year has been pretty hot in the States. Our OpenMicroServer is already controlling things like a conveyor belt for sushi, so why not a water pump for a ranch in California?