Ron gets a bug-zapping no-prize for bringing us this report of a new robot with a distinctive power supply:

A British-built robot generates its own power by gobbling flies, but it has a stinky downside — it needs human sewage as bait to catch the insects and then digest them.

Which means you definitely won't be using it to vacuum your house, but I think it might make a nifty addition to, say, a campsite.