Yeah, for my part I had a constant ssh connection to a screen session on my machine at home, and could work on all kinds of hobby projects from the office when I wasn't in the mood to work and had to still be present. Whether I was there had nothing to do with it - when motivated I've often done some of my best work from home in the middle of the night because I wanted to and inspiration struck. Either way, my boss would only know if the actually engaged with me rather than go by whether I was typing. Since I love programming, but sometimes not the programming I have to do at work, I've had many managers who could've stood there behind me watching me "work" and still be unable to tell if I was slacking or not.