It seems to be getting harder and harder to find GoDaddy coupon codes that work, so I’m going to post them here whenever I find ones that do work.  Here are a couple in case you’re having the same problem:

cjcchp10 – 10% off

gdz1112b – 30% off

Update for February.  Needed to do a renewal and found this code which gives 30% off renewals on GoDaddy: gdbb776

Worked for me on February 5, 2011.