Allow ideas to be posted for all, and those most applicable to rise to the top, like sweet cream in the corporate milk. Rate those public solutions by whether or not they actually worked. Then publicize how they were applied, indicating their rating by stars for successes, and bombs for failures. 5 stars is a winner, 5 bombs is also a winner, because we learn, sometimes, most from failures than we do from successes.
To tear down the hierarchy, have a publicly accessible area on your intranet (or to all on the internet if you are brave enough to open source your entire operation), where folks post their best ideas. Allow those ideas to be tested by the true acid test - practice. If they work, or need modification to make them work, allow others to tweak them. Then rate those ideas with success stars 1-5, where five is the most applicable. Don't just promote those that succeed, promote those that fail, as the essence of swift organizational learning is quickened by what we learn from failure; not just by replicating success.