For the last 15 years, it's been an M3 with a 50- usually the DR 'cron, and a spare roll of film or two in my pocket. Sometimes I carry a small handheld meter, sometimes not. If I really anticipate a photographic opportunity, I may grab another lens better suited to the situation, but I don't like carrying more than two lenses unless I'm working (and then I'll have a couple of bodies and other gear, too). For the last few years, my minimal travel kit has been an M3 with a 50, a 21mm with finder (the little CV LTM one) and an Olympus XA with an A11 flash. With a few rolls of film and a small meter, I have 21-35-50 lenses with two bodies and flash capability all in a really small kit.