Plugin that allows users to vote on suggested new features

Hi,

On several sites (such as salesforce.com) I've seen a fantastic feature - which allows users to submit a suggestion for a feature they want you to develop for whatever it is you're selling them... and for other users to then vote for that feature.

The popular ideas float to the top and you can use this to inform your development roadmap.

Is there such a plugin already developed for this? Or would you consider developing one?

cheers, Andrew