I just found a MacGyver reference I've never heard before.
Apparently smokers who fabricate smoking devices (pipes I guess) out of whatever they can find laying around are called MacGyver Smokers.
According to
this article, Brad Pitt is one.
I'm (perhaps naively) assuming they're talking about smoking tobacco here, although being that we're talking about Hollywood, it may well have been something stronger, which makes the MacGyver reference all the less appealing.