I always have free pounds, as my pack weight has dropped another 4# since reaching the point that I don't even notice my pack any more. Further lightening and simplifying everything remains an ongoing process that is kind of a hobby unto itself rather than fulfilling any real need as far as backpacking goes.
A knife and saw for fire when I want one are really the only extra gear I'll add unless combining activities, but sometimes I'll take a couple pints of my favorite sweet tea, or some apples and packages of that Jif chocolate silk for snacks.
For short overnighters where I play a lot, having light gear sometimes means being able to bring wetsocks and watershoes, even wetsuit pants, or heavier pack and rope with gear for rappels without feeling weighed down. I don't really keep track of pack weight any more, but doubt it broke 30# either time I carried a 150' 11mm static line to rap waterfalls this past summer.