Planet13 - 3:41 pm on Jan 4, 2012 (gmt 0)
I think that you are probably already doing what you need to do to be seen as an authority; getting links from relevant sites.
The only other things I can think of are getting links from high authority sites that may not be related directly to your niche (i.e., a link from a NY Times article).
And although it probably has been reduced significantly lately, I still believe that having a keyword in the domain name is at least a bit of an authority signal to google.
But ultimately, if the CONTENT is unique and authoritative, then the quality of the content will help with creating authority.