Site Level Wiki?

Is there a way to turn on a Site Level Wiki instead of the Home Page?
I have multiple projects so the thread about "Single Project Site" doesn't apply.

What I would really like is the ability to have a Site Level Wiki that can reference all the project Wikis.

I am sure this is possible and most likely simple to implement, all the Site really needs is a "Wiki Start page" which could be sett in Settings at the Site level, with an optional use for Home Page checkbox.

Then I could at least have a Landing page there instead of being forced to view Latest News and Latest Projects which are of little help to my site.

There are some security problems about referencing issues and wikis from one project to another as well as membership, but those really would be fine to just let the wiki launch there and the site should already control enforcing the login anyway.

Another option would be to just let me have more control over the Home Page (similar to how the My page works)