Ignoring the trolls, people seriously saying they're for women, that only losers wear them, etc. etc. should hitch a ride off the farm and explore the Big City once in a while.
I don't need one of these yet since I don't have to take a laptop to work at the moment, but it's getting to where I need to take one of those shitty little nylon pull-close backpacks with me to hold some of my notebooks/my kindle/my water bottle and I envy messenger bag users. My commute includes walking, driving, taking an aboveground train and taking a subway, and I could definitely use one in at least 3 out of those 4 environments. This thread has put out a lot of great suggestions. Thanks, bros. (I ended a sentence with bros? Who does that. Me, fuckers. That's who.)