depending on where you live short hair can be your savior. im used to cold weather but was moved to Florida, so whether i like it or not ( which i do

) i need to have short hair to stay somewhat cool.
I used to keep my hair really short, and after looking at a lot of photos of me like that, I realized how uninteresting it made me look, and generally speaking, I think I look better with longer hair. Granted, I've cut my hair down quite a bit in the past month or so (nearly shoulder-length before), but it is short for me...
...On the subject of short hair working, yes, there are cases when it was necessary. Back when I was racing bikes, I used to cut all my hair off once the weather was consistently above 60 degrees, as it was just too hot to have that much crap on top of your head when you're running around at 20-30 MPH for 40 Miles or more. Beyond that, when the weather gets hot, it isn't the best to have incredibly long hair (particularly at work), but I never cut it completely off either...
I'm planning on keeping it at its current length for a while. When I go down to Miami this summer I'll probably trim it again, but it will still be 'long' by most people's standards...
...And my "girlfriend" (nothing is 'official' between us, but we act like we're going out) hates my long hair. Its a battle, but the trim from not too long ago helped her out a bit I guess...