The Petri Color 35 is very nice and all manual, but it's from the '60s and all metal so no lightweight.
I find that a lightweight mostly plastic capsule camera works best for carrying in a pocket.
Many of these have autoexposure, most often aperture priority or program AE and
zone focus, which - with practice - works far better than hit or miss AF in my experience.
Models I have owned and recommend include Minox 35ML, Ricoh FF-1,
Olympus XA2 and XA3, Chinon Bellami, Voigtlander Vito C/Balda CA35.
Here's a website for fans of modern miniature film cameras:
http://www.subclub.org/
Chris