Are you an Inventor?

I was walking to the train station this morning and a random thought ('twas cold....thinking of stuff to get my mind off the fact that am freezing) about inventions came to mind.

I remembered how I read about this guy who invented coloured bubbles - it took him 11 years to perfect his invention. Then it got me thinking, if I was to invent something, what would it be? Here are some suggestions (dunno if they have been invented yet)......so here goes:

• How about non-toxic paint that is graffiti proof?
• Etch proof glass for buses that is reasonably priced - if you are in London mainly (dunno about other cities), look at the windows on top of the double decker, esp. at the back.

What would you invent if given the chance?