Boxing clever for Suggestions

I am not a lover of suggestion boxes...though it is a start, I have to admit that in getting feedback. The problem tends to be that they become moaning posts so what about having two!

One for problems/threats
One for solutions/opportunities

This builds into the culture a sense of acccountability and responsibility for driving improvement. Post the problems that people see and get them to suggest improvements...with the winner being based on the solution rather than the issue.