The Umbrella Water Gun, from Alexy Woolley Design, is what's created when an umbrella gets drunk one night and goes home with a hussy of a water gun. The unit collects water in the concave top, which travels down into the water gun handle -- so you never run out of ammo as long as it's raining! Brilliant. Just add some dye or food coloring to the reservoir to really piss people off. Just make sure you're wearing running shoes, because if I get sprayed I'll take that umbrella and ram it so far up your ass you'll die of dehydration.
One more after the jump of people who don't understand when to use an umbrella.
Umbrella Water Gun: A Weapon and a Shield All-In-One [uberreview]