In my case, I have a very small place, a motorhome to be exact.  I'm solo, I
own it outright so there's no snoopy apartment managers, I'm in a *very*
low-theft rate spot (as in, none in the trailer park for over 10 years...so
I do free-run.  The guys love it.
 
There is also a "hybrid" style of caging, where the ferrets have free run of
a fairly small, well-controlled room such as a kid's bedroom.  Then, a small
hole is cut in the door and a long plastic tube is connected to a *cage* in
the living room where everyone is.  The fert(s) can go anywhere between
"their room" and the cage, plus they can be let out beyond that during
supervised playtime.
 
This sort of "semi-cage" setup helps eliminate classic problems like
recliners and "eating something weird".  If you have roomates, this setup is
very good at limiting the fert's access to the non-fertowner human's areas,
and done right, it will speed ferret-finding in fires; it's not too
effective for theft.  Honestly, most of you who do cage don't have a
theft-resistant cage like one the very fortunate "pro-cage-person" had, that
defeated a screwdriver in a recent post.
 
Anyhow, consider the "semi-cage" in some circumstances.
[Posted in FML issue 1598]