In order to stay sharp and have fun, I thought it would be interesting to have a thread where everyone could post riddles for other members to solve. So if you have an interesting one (it can be a riddle you heard somewhere or one that you invented), just post it here. Whoever solves it should add one of his or her own. Here is a simple one of my creation to begin with.
When you do nothing, I go to waste,
When I’m insufficient, you make haste.
What am I?