Idea: Community Sponsored Software Development

So I had this idea today, think:

Digg (community voting) + Ebay (reputation system, bidding) + Paypal (payment gateway) + Social Networking for open source software development.

Let me give some background information:

1. I have my Powerbook and my iMac. I want to sync my address book, calendar, etc between them. The easiest way would be to pay for a .mac account ($99.00/year). However, I’m cheap and the only other way is to use a few hacks. I was thinking, hmm… make an App that can use a public, centralized, secure and personalized storage like Amazon’s S3 that is open source and free.
2. Anyways, I need an app that can use a secure online storage to sync my two computers.
3. I don’t know how to build Mac apps and would rather pay a small fee for somebody else to build it.
4. Small fee = $10.00 bucks (one time)
5. 10.00 = 2 cups of starbucks
6. Get 1,000 people to contribute $10.00 = enough $$$ to pay a decent developer to build the app

So how to get 1,000 people to contribute $10.00? We need to create a 3rd party entity that:

1. That holds the money in escrow for the People to be paid out to the Developer upon successful completion and delivery of the Product.
2. Upon completion, Product is open source licensed and available to all.

Of course there’s always the component of trust. This middle man company has to pay their bills somehow so perhaps a transparent management fee would be in order to keep everything running. Comments would be appreciated. Even better if something like this already exists, please link me.