Google has so many services out there that many users tend to forget about some of them. A good example of one that falls into that category is Google Moderator, which is a service Google released back in 2008 as a way for users to create a suggestion-focused website.
In some ways this reminds me of Reddit or the original Digg since users are able to submit and vote on their favorite topics. I think there are a bunch of areas that a service like Google Moderator can come in handy including a support site or when planning an event. If you are, for example, trying to plan a company party you could let people submit their ideas for the party and vote for the ones they care the most about. Plus you can embed your Google Moderator page into your own site using the instructions provided here. They used to have a full API for it, but that was officially shut down about a week ago.
The reason I was reminded of Google Moderator was because one of the recent U.S. Presidential debates asked the community to submit and vote on questions they wanted the candidates to answer. Back in 2008 when Obama was running for President his team used Google Moderator as a way to solicit questions from the public. At that time he attracted over 4 million votes from over 100,000 users.