Ok, don't tell the IT guys I'm saying this. But, you know an easy way to keep your food warm? Put it next to your PC tower. That thing gives off a lot of heat. Or at least the ones that really need updating (ahem) do.
I had whole wheat rolls and butter pats (saved from take-out) for breakfast the other morning. They were cold from the fridge, but after half an hour next to the PC they were nicely warmed up. I also use this method for keeping my toast warm (yes, it takes me so long to eat toast that I actually have to keep it warm).
It doesn't work that well for liquids, and certainly doesn't keep things hot. But for a quick fix, it works pretty well.