There's a GREAT PDF file from Colorado Springs that has all sorts of useful information, and a big section on bug out/emergency grab and go/keep in the car bags. One of the best I've seen actually.
http://www.springsgov.com/units/fire...ty%20Guide.pdf
Check it out, I was going to use it as a base for redoing our gear. Some of the things such as important documents, I recently scanned in everything into PDF files, saved them to a truecrypt encrypted drive, and stuck them out into the "cloud" for safe keeping.

With firearms, it's a little weird, since I think that officially you're not allowed into Red Cross shelters and such with a firearm, but I'd definitely want one. Since concealed means concealed, does anyone stash an old pistol with a couple magazines into some hidden pocket in your bag?