I like Zvex's designs, pictures of cats and beetles...it's not what you'd expect. The nuke sign is OK, but it seems a bit cliched...not so individual, if you get what I mean (no offence meant)
Why don't you silkscreen black and white photos of dead celebrities on to them? I think that would be cool, 'Dead Celebrity Pedals'. I'm serious...
As an aside, a friend of my bassplayer has apparently started making pedals too. He tweaked an Ampeg Scrambler so that the octave up feature descends after a preset amount of time. It certainly sounds interesting...
I think the problem with those kind of off-the-wall FX is that they are so individual that you can't use them too much. Invariably they are often the more expensive pedals, so it's hard to justify spending so much on a pedal with limited use. For instance, I love the sound you can get from a Zvex Seek Wah - it sounds incredible. But I couldn't use it repeatedly, maybe only once a gig or something, just because the sound is so distinctive. So I'll probably just end up getting another standard wah instead, because the sound of a wah is so typical within rock music that it's ok to use it multiple times during a gig; the Seek Wah is so original in sound that you couldn't get away with it.
The pedals I want to see are pedals that have a great and useful main use, but with the ability to do something wierd and out of the ordinary at the flick of a switch. :)