Real postings, I mean. For now, here's a tiny little NZ anecdote I just posted to Chit-chat on BookCrossing.com:

I read that Dunzy (a fellow BC member) was not well, and wanted to send him a card... so I picked a nice one, and had Stoneshop and Rubberchicken sign it too.

I meant to post it at the airport before going to New Zealand, but forgot... and found it in my bike jacket pocket, after riding through half of the South Island. So I decided to stick an NZ stamp on it in addition to the Dutch ones, and mail it from there.
A hundred kilometres later, it was still in my pocket!
Eventually, I left it on a table in the communal kitchen of a motorlodge in Haast, with a note that said 'Please mail this, thanks'!
I thought, since things like the honesty box system seem to work here, I may as well give this a go. Someone may well mail it.

Looks like someone did. Because yes, my friends, that card got to Dunzy in Canada.