This week marked the official debut of Spot Us, a web site that seeks to prove that crowd-funding could be a new model for the clearly-ailing news business.  Essentially, the site posts potential news story topics - in-depth and rather investigative in nature. and right now, limited to the San Francisco Bay area - and asks for contributions to pay for them to be reported and written.  Right now, the site is seeking $1,000 to fund a story on the Oakland, Calif. police department and as of this writing, has raised $75.  The site has been launched through a $340,000 two-year grant, so it does have time to prove itself.  It will be interesting to watch the progress of this …