Sometimes, the best interaction design, is NO interaction design
Recent user testing of a client website demonstrated an issue with a tricksy form control. We redesigned it to our satisfaction BUT in an epiphanous moment we asked if this control was necessary at all?
It took a couple of days to get approval but eventually the control was removed altogether and our client made a lot of money.
20th century French writer Antoine de Saint-Exupery sums it up nicely:
“Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.”