Here is my idea:

  Create a way for one person to pose a problem, or a challenge or something that needs people to accomplish it.

Then people with bitcoins can look through these problems and if they agree that they too want to be involved, they can pledge their own bitcoins towards that problem.

Everyone will be able to see how much is pledged toward the various problems and as the pledges reach a certain large amount, then people with solutions will start to pose their solutions to the problem.

The people who pledged toward that problem will be able to vote for the solution with their bitcoins.

If enough people vote with their bitcoins toward a particular solution, the solution gets funded and the problem gets solved. If not, people get their funds back and wait for the next solution to be proposed.

I call it BitPools