Dave Gorman - really funny comedian - is hosting a new show on Radio 4 and they're looking for genius ideas. I'm pretty sure people on this site can come up with some more for him.
http://www.bbc.co.uk/radio4/comedy/genius.shtml
They're not looking for clever inventions as such, just those brilliant ideas that would be incredibly useful.
I submitted this idea.
Traffic lights and a road marking system in supermarkets.
Has anyone here got any better ones?