Back in 2010, Scott Sigler (aka the Future Dark Overlord) ran a contest to come up with iconic logos for the teams in his Galactic Football League (GFL) series of books.  In all, there were a possible 18 teams up for grabs to the lucky fan/designer with enough skills to attract his attention.  The lucky winners were able to get their logos published in The Starter, the second book in his GFL series.  I think I ended up submitting over a dozen, some with multiple versions, though I did end up snagging bragging rights on 4 of the teams, which can be seen below.