Have to agree with this. I'd rather spend only work hours on tech du-jour. I spend plenty of my own time on math/CS/<techs that I'm personally interested in>,

Have to agree with this. I'd rather spend only work hours on tech du-jour. I spend plenty of my own time on math/CS/<techs that I'm personally interested in>, and I think companies benefit from those as they make me a better programmer - but most/all? companies don't really appreciate and never reward those efforts 'cause those aren't the latest fads <sigh>.