Not a lojban original, but much funnier and more easily adaptable in lojban! This can be better written, but off the top of my head:
za'a pa no lo prenu cu zasti .i jimpe be lo cmacrbaineri .i na jimpe
Actually, I'm pretty sure that's mangled. Probably need something to tie it all together better. This job is killing me...
Anyway, it's the old joke "There are 10 types of people in this world - those who understand binary and those who don't." The humor is conveyed better in lojban because in spoken English, saying "ten" doesn't quite have that numerical ambiguity that saying "pa no" does.