Hm, I have been buying up a storm on Ebay, of camping/surplus gear, not that I am building a panic bag but the items will be packed in a pack and stored in my locker so it would be ready at the drop of a hat so to speak. Mostly it is a MOLLE pack with a (large) number of additional packing compartments but I have also bought a few other trinkets including water tablets, fire steel, some first aid kit additions etc. The last ticket item I have my eyes on is a Katadyn water filter.
The other things you mention like knives, waterproof strike anywhere matches, flashlights etc, I have a bunch of them around the house already, no need to squirrel them away, heck the boy would likely find them and drain the batteries anyways, if I decided to hide them. When I leave them out in plain sight, he seems to not care less about them.
In regards to salt and stored food, I bet we could go a month with the canned and other non perishables we have in the pantry closet.
In regards to personal protection, I have been considering getting my restricted firearms license (for hand guns, I have a non restricted which allows rifles, shoguns and crossbows) but between the course, the exam and actually buying a firearm, its a whole bunch of pennies, nickels and dimes added up, I dont have the disposable income for it at the moment.
Andy you mentioned HAM radio, is there a handheld version of such a beast? Whats a good basic unit? Erik? Input?