Douglas Adams satirised precisely this point with his Zaphod Beeblebrox character in Hitchhiker's Guide to the Galaxy. To quote wikipedia[1], his was "a role that involves no power whatsoever, and merely requires the incumbent to attract attention so no one wonders who's really in charge, a role for which Zaphod was perfectly suited"

[1] http://en.wikipedia.org/wiki/Zaphod_Beeblebrox