Kickstand, a collapsible coffee stall that’s wheeled around on a pair of salvaged bikes, made its public debut last Saturday in Williamsburg, Brooklyn, at the Market in McCarren, the outdoor arm of Artists and Fleas. The brainchild of Aaron Davis and Peter Castelein, both employees of Gimme! Coffee, and Neal Olson, formerly of Gimme! Coffee, Kickstand brings fresh, hand-crafted coffee to the grassy splendor of a public park.