Remember that part in Willy Wonka and the Chocolate Factory, where the candy master hops on that bike, which stirs the "gives it a little kick" solution in the inventing room?
He sings: In springtime, the only pretty ring time; Birds sing, hey ding, a-ding, a-ding; Sweet lovers love the spring
That was always my favorite part.
Anyway, bikes that do other stuff are cool. Especially this drawing machine bicycle by Joseph Griffiths.