I just found another fun thing to do on a flight! Thanks. Hmmm...how much
would I freak out a flight attendant when I pull out my laptop with a psia
transducer and start logging data? Is the baggage compartment
unpressurized? I could compare data with a remote logger after the flight
WIFI is frowned upon.

I've monitored the pressure altitude on quite
a few flights on various airlines and have noticed quite a bit of
variation. Some flights were kept very close to the 8000' limit
(around 7900'), while the lowest I've seen while at cruising
altitude was around 5500'.