$100/hr, albeit writing about/for software, not writing the software itself. Copywriting is a super great gig.
How did you swing that/who do you write for?
I have written an article for Sitepoint and have a couple in-progress pitches with them and someone else, but I am not really motivated about it because the per hour rate, after all the back-and-forth and work, ends up being like 20 bucks or less.
As you allude to though, the back-and-forth does dilute the rate quite a bit. But it's still fun as hell.