I love the idea behind Kindling. It encourages democracy and collaboration with a leaderboard-style interface. Anyone can pitch ideas and vote on all the projects in the system. But here's the clever twist: You don't have an unlimited number of votes. Everyone has a budget (the default is ten votes) which you can spend any way you want -- sprinkled around, or even blow them all on a single idea. Those with more votes float to the top, while less popular ideas tend to fade away. When an ideas is approved, individuals can even take responsibility for making it happen.
Kindling comes with all sorts of reports and views, so you can see statistics on the ideas that have been submitted as well as how individual users are participating. Unfortunately, Kindling isn't free -- up to 40 users can subscribe for $49/month. There is a 30 day free trial, though, which is enough time to evaluate it with some real-world project management.