I'd imagine there are other places to get them, as I see people with hard copies quite often (subscriptions maybe?), but whenever I need one (usually before a show), I just download it as a PDF for $4 from: http://www.greysheet.com/
That's actually a really good idea. I have a smaller camera bag (designed for an SLR with a decent-sized lens) that would probably work well for this. I'm not sure if it would be big enough to hold proof sets (one of the current things I'm buying), but if so, it would work well. Thanks.