Poolside parties. Backyard luaus. Outdoor concerts. Like peanut butter melds with jelly, certain soirées seem to go hand-in-hand with Summer. But I'd argue that there's no better way to pass the long, balmy days than to gather friends for an impromptu picnic. In true spur-of-the-moment fashion, any fare goes — but there are some old favorites that come to mind. Here, 10 prototypical picnic foods that fit the bill for a reason.