hitch locks

I think you pinned it down.

We've never used a lock when parked at a campground, even if we're going to be gone all day.  But I always put a hitch lock on when it's parked in storage.  As noted, it will not prevent theft, but at least it will slow the thieves down by, say, 30 seconds.  They could use a bolt cutter to take it off, or even easier, just hook up the camper to a vehicle using the safety chains. 

If you want to slow the thieves down a little more, you can use a wheel clamp lock (sort of like one of those boots they put on cars that are illegally parked), such as this:  http://www.amazon.com/gp/product/B005FG1AG2?colid=3H0QPNY906XIR&coliid=I39IH9IHV92JI3&ref_=wl_it_dp_o_pC_nS_ttl

Generally either a latchable pin, or lock, is placed in the latch while towing as a backup to ensure the latch doesn't jump up accidentally.  However, don't count on that lock preventing someone else from driving away with your pod - it is actually very easy.  Really it is just to show your insurance company that you took "due dilligence" if something happens.

We are starting on our first big adventure - 2 months across the country.  We have a tongue lock for when the pod is not on the car but do we need a locking pin for the hitch to the car or on the trailer coupler?  Any suggestions?