I use my tripod for landscapes/sunrises, sunsets and for long exposures. I've got a carbon fibre Manfrotto so it's pretty light and I've got a decent head on it (unlike me, my head is awful to look at). I'd say I use it over 50% of the time as I have time to get the shot right. The rest of the time i'm wandering around the city and just taking random snaps.