And, yes it's old school. But, it works!
Grossman recommends that when you have something you want to get your employees' input on, post a question on a flip chart in your department or office. Provide Post-it notes, and watch the ideas grow as employees post their ideas on the flip chart.
This is an informal focus group of sorts, where employees can freely and without feeling pressure, share their ideas, see others' ideas, and then suggest even more ideas.
You'll get great collaboration without a meeting!