Answer:
What is the difference between a poorly dressed man on a bike, and a well-dressed man on a unicycle?
What is black when you buy it red when you use it and gray when you throw it away?
I am a mini solar powered computer.
I am lighter than air, but a hundred people cannot lift me. Careful, I am fragile. What am I?
What jumps when it walks, but sits when it stands?
Why is the letter B always cool?