I'm on it like a shock jock on unoriginal racial slurs
I would love to say that someone stole my idea, but the idea is actually from Blade Runner. But I DID say it should be lit by LEDs which could have the batteries in the handle. It looks like someone else figured out the same thing too, only they got off their ass and did something about it! Think Geek is now selling a LED Umbrella for 24.95. Forget the fact that you'll look like a citizen of an 80's vision of futuristic dystopia, with that light on, you can dart around on dark and rainy SF streets and actually been seen by the onrush of cars (and then get hit by them, but at least they will see you).
ps. Deckard was most certainly a replicant!