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Essentially, this one allows you to:
Retrieve user information for blog owners in a basic WordPress MU environment. Can retrieve the current blog owner’s user information, specify the blog by ID, or retrieve owner information for all of the blogs in an array!
Easily integrated with any template by using the two functions provided by the plug-in: get_blog_owner and get_blog_owners.
When retrieving multiple owners, you can specify the number of owners to return and sort by blog creation date, most active blogs, or most recently updated blogs; the key for each item in the returned array matches the ID of the blog!
Practical uses include featuring the blog owners (perhaps by most active blogs) in a site wide template, or highlighting the blog owner inside their individual blog.
Pretty cool, you can download it for free from here.