Summary:  Returns an unordered array of blogs on the domain.

Detail:  This function first checks for the existence of a site_option called “blog_list,” and verifies that the option is no more than sixty seconds old.  If the option does not exist or is older than sixty seconds, the database is queried for the blog list and the option is set.

The $num variable sets the number of returned blogs.  The results can be offset using the $start parameter to tell the function how far down the list of blog to start.

If $display is set to ‘true’, as it is by default, the function will return an array of <li>’s for output to the page.