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).

If it is an ecommerce site, then having things like your physical address and other contact info, as well as your privacy policy, accessible from the home page, might help give your site authority.

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.