Regular expression generating the language $L=\{w: |w|\le 5\}$
If you are allowed to use $\epsilon$, then you can represent "0, 1, or nothing" using $0+1+\epsilon$, and using this it is easy to come up with a short regular expression.

If you are not allowed to use $\epsilon$, then you can use the fact that $L = \bigcup_{i=0}^5 \{ w : |w|=i \}$ to come up with a fairly short regular expression, though I don't know how you would match the empty string.