American, Untied, USAirways, Continental, Delta, Air Canada. AeroMexico, Qantas, Air New Zealand, MaxJet, Silverjet, Aeroflot, LOT, Alitalia, all use 767s.
Properly maintained, a 767 (or a 737-200 for that matter) can remain in flying condition for quite a long time. From a pax perspective, a 767 beats a 757 every day in my book.