I don't really have a reason for picking GPL. Would you prefer MIT instead?
MIT is more widely known and understood, though.
here are two very handy articles about the differences between open source (and other) licenses
http://www.smashingmagazine.com/2010/03/24/a-short-guide-to-...
http://en.wikipedia.org/wiki/Comparison_of_free_and_open_sou...