I was looking over this thread and there are some great ideas here. If you don’t mind my rambling, I’d like to toss in a few ideas of my own. Sorry if I accidentally go over any ground that's already been covered by anyone.
For lockpicks, I think you have the right idea, keep the kit small, but in my opinion, bypass tools are even more useful than picks out in the real world. In addition to the picks I'd pack a couple of pieces of strong steel wire and some plastic or mica latch shims. They hardly weigh anything and take up very little space. Maybe also the small size EOD Pry Bar if you have room.
I think your hammer might be a little bit impractical in this situation, but if it’s something you really want, consider a Stiletto TiBar (12”or 16”). It’s much lighter to carry than a steel hammer, has a hammering face, a pry bar on the end and a mean claw on the back as a weapon or forced entry tool. If the high price tag dissuades you, look at a Stanley FatMax Xtreme FUBAR instead. It’s similar to the TiBar, but steel instead of titanium, and much, much cheaper. I’d prepare it in advance with an angle grinder by chopping off the smaller spike on the back (look at a pic, you’ll see what I mean) and you basically have a small version of a Halligan bar for forced entry. Plus, it’s a mean looking weapon. Unfortunately it’s still heavy like a hammer, but it’s much cooler. The FUBAR is available in 4 or 5 variants depending on what size you want.
Consider that for about the same weight as the hammer, you could pack a good entrenching tool and a camp saw instead. Both would be very handy for building longer-term shelters, traps and water gathering systems. If you get the right kind of shovel, something like a Spetsnaz shovel from Cold Steel, it’ll also be about as good of a weapon as any hammer. Split zombie skulls like a champ!
You have the water purification pills covered, but you might want to pack a few coffee filters, folded up really small and tucked away. They won't filter out biological elements, but if you can't find totally clear water, pre-filtering it before purifying can make it more palatable and boost your morale.
In the event you find a good water source, you'll want some collapsible water containers to take full advantage of it and carry as much with you as is practical. Some of the ones available out there are very compact when empty.
I'd add a metal canteen cup or small camp pot for boiling water and cooking. You can pack stuff inside it so it won’t take up a lot of room in your bag. You don't want to rely on purification tablets exclusively. You'll run out eventually.
If you're going to carry a second handgun that's a different caliber than your primary weapon, I'd suggest a 22lr for the second one, preferably suppressed. You can carry a LOT more ammo that way, and you can hunt and defend yourself without as much unwanted attention.
As suggested by someone else above, take the bare minimum of gun cleaning supplies:
some CLP, a t-shirt (cut it up for patches, or use it as an extra layer of clothing in a pinch), a toothbrush and a Boresnake.
For your knife sharpener, I’d take an Eze-Lap diamond hone. Non clogging, very fast, and can put a very nice edge on things. Available in many sizes.
First aid: add a couple of military surplus trauma bandages.
Pack some Immodium or other Diarrhea medication.Your food/water quality won't be ideal, so diarrhea is a big risk and the subsequent dehydration is a killer in a survival situation.
Remember your Excedrin contains aspirin, a blood thinner. Be aware of that in case of injury.
Some chapstick can make things more comfortable for you as well. It's good for more than just lips, and is available with some SPF.
A lightweight waterproof hooded poncho can make life a lot more comfortable. Something like a US military surplus one. It’ll keep you dry, keep the wind off you and you can use it as a blanket at night. It can also help to camouflage you or your gear in a hurry.
A small signal mirror could be handy. If you want to remain in hiding and don't need it for signaling, it'll give you an unbreakable mirror for personal hygiene.
You mentioned you have some extra room in your backpack. Consider taking a small duffel bag folded up in that space. In the type of scenario you’re talking about, you will be scavenging to survive. If you get lucky and find someplace with a lot of stuff you need, you want to be able to carry as much of it away as you can. It can also be stuffed with grass or something to use as a pillow at night.
Don't rely on just one method of starting fires. In addition to your magnesium starter (I assume yours has a ferrocerium rod for making sparks to ignite the magnesium), also carry a lighter, or perhaps a "Spark-Light" fire starter, which is a little flint striker in a plastic box with some tinder. Make sure you carry at least one of your firestarters on your person in case you’re separated from your bag. You should also learn, AND PRACTICE, an improvised method of starting fires. My favorite is the bow drill method. There are a couple tricks to getting it right and you'll be better off if you've learned those tricks before you are in a tight spot where you need it to survive.
I'd double how much paracord you're carrying and take 100' instead.
Carry several large clear garbage bags. Clear, not black. They have many, many uses from ponchos, shelters, waterproofing your gear, keeping gear and yourself afloat in water, making several different types of solar stills, etc. You can fold them up really small and they take up very little room when you pack them.
And lastly,
“The Hitch Hiker's Guide to the Galaxy has a few things to say on the subject of towels.
A towel, it says, is about the most massively useful thing an interstellar hitchhiker can have. Partly it has great practical value - you can wrap it around you for warmth as you bound across the cold moons of Jaglan Beta; you can lie on it on the brilliant marble-sanded beaches of Santraginus V, inhaling the heady sea vapours; you can sleep under it beneath the stars which shine so redly on the desert world of Kakrafoon; use it to sail a mini raft down the slow heavy river Moth; wet it for use in hand-to- hand-combat; wrap it round your head to ward off noxious fumes or to avoid the gaze of the Ravenous Bugblatter Beast of Traal (a mindboggingly stupid animal, it assumes that if you can't see it, it can't see you - daft as a bush, but very ravenous); you can wave your towel in emergencies as a distress signal, and of course dry yourself off with it if it still seems to be clean enough.
More importantly, a towel has immense psychological value. For some reason, if a strag (strag: non-hitch hiker) discovers that a hitch hiker has his towel with him, he will automatically assume that he is also in possession of a toothbrush, face flannel, soap, tin of biscuits, flask, compass, map, ball of string, gnat spray, wet weather gear, space suit etc., etc. Furthermore, the strag will then happily lend the hitch hiker any of these or a dozen other items that the hitch hiker might accidentally have "lost". What the strag will think is that any man who can hitch the length and breadth of the galaxy, rough it, slum it, struggle against terrible odds, win through, and still knows where his towel is is clearly a man to be reckoned with.”Ok, maybe you don’t want to pack a towel, but an oversized bandana (or keffiyeh, shemagh, etc… pick a name you like) can be very handy.
Here are a couple links where you can get some of the survival gear I mentioned.
http://www.countycomm.com/whatsnew.htmlhttp://bepreparedtosurvive.com/SurvivalProducts.htm
Tue Mar 22, 2011 6:28 am 
