Mxsmanic wrote:
In small aircraft, if I understand correctly, there's no law that says
you can't put anyone you want in the right seat, as long as there's a
licensed pilot in command.

There's no requirement that you can't put them in the left seat. It's
commonly done when the right seat pilot is also a flight instructor,
but it could be any legal pilot.

So, what are your right-seat policies? Do
you put passengers in the seat?

Most people treat the right seat as the first passenger seat. I'll
let anybody sit there. If they show an interest in aviation and
conditions don't contraindicate it, I'll let them fly. For those
really interested, I'll let them operate the radios etc...

If you're married, does your spouse ride in the right seat? If so, is
he or she a pilot, too? If you have kids, do they ride up front?

My spouse is half the time in the right seat, and half the time in
the left (she's also a pilot). I've let my kids fly in the right
seat as welll.

Some people are prone to motion sickness if they aren't riding in one
of the front seats of a car. Is this true for aircraft, too (that is,
are there people who get motion sickness in a small plane if they
aren't riding up front)?

Definitely. The forces of the plane work around the center of
gravity which is usually some where around the back of the front
seat. The rear seat of some aircraft will drift around a lot
more than the front. The closest I ever came to being sick in
a small plane was riding in the back of a 182 on a gusty day,
lots of swinging back and forth.