Great stuff! I stumbled upon this article while writing the evaluation of my software sabbatical - http://www.erisc.se/software/2012/08/14/software_sabbatical_evaluation/ I think one approach worth looking into is to spend this "goofing off" on longer periods of time instead of just chunks here and there, just to get some distance from the drudgery mentality of bug fixes, deadlines and release schedules. I've experimented with this a bit, and even if I haven't found anything revolutionary I definitely feel there's something to it.