Right now I'm designing a lettuce table so I can grow organic lettuce in my garage, and petitioning my local Costco to start carrying Ecos laundry detergent so I can hook my washing machine to the house's graywater system. Both of those ideas are very tame, though.
My actual "brilliant" idea for the last few months is recording a Christmas album, then self-distributing it...merely by shipping it to friends across the country and asking them to casually walk into record stores, drop a few copies on a shelf when no one is looking, then walk out. And just see how long it takes before anyone notices. The original idea was to give copies of the album to extended family members I never see, and then play it completely straight...pretend like I want to be a singer and ask for their honest feedback, and watch them shift uncomfortably while trying to figure out a nice way to phrase it. I decided that the record store idea was funnier.
UPDATE: How hard is it to crack a fucking egg?