Use solar to disinfect:

Recent Advances in Solar Water Pasteurization; Boiling isn't necessary to kill disease microbes, solarcooking.org

Synergistic effect of solar radiation and solar heating to disinfect drinking water sources, Rijal and Fujioka 2001

Drink up before leaving camp:

Get as hydrated as possible before leaving camp. Even if you end up peeing extra along the hike. Being hydrated from the start means having to carry less water in your pack.

I still don't trust that they have made soft, collapsible bladders to be toxin free. Any plastic will be leaching toxins. I certainly don't like the plastic taste. I use a 3 stage filter, including carbon, at the end of the tube from my internal water bladder. Carbon filters out a good percentage of the plastic toxins. As an added bonus, this setup doubles as a gravity filter.

Some trips require that I carry as much water as I can. So I would also need a bottle in each side pocket of my backpack. In my dreams, there are lightweight soft bladder-bottles made of titanium or stainless. I don't think they exist. Do I make due with plastic bottle bladders?

nsharry61 on WhiteBlaze enlightened me to the existence of soft bladders that are coated with metal or glass on the inside:

“As I understand it, Mylar is metal coated plastic with the plastic being there to provide structure to the micro-thin metal layer. In the case of the wine box liners, I would think the metal layer is likely on the inside to prevent any plastic taste from leaching into the wine.

On a completely alternative note, Specialized Bicycles manufactures a series of water bottles that are called Purist(TM). These are a flexible LDPE plastic bottle with a micro-thin layer of glass deposited onto the inside to prevent the plastic taste from getting to the water. It also reduces staining and bacterial build-up on the inside of the bottle.

So, as long as the lining is thin enough (a couple molecules thick?) and you don't mind using plastic as the primary structural material, it seems you can potentially get both collapsible glass and collapsible metal containers.”

With most people taking soft bladder-bottles, having a separate cooking pot makes sense.

If you are wanting to rehydrate food by cold-soaking, you are going to need at least one container with a wide mouth for easy cleaning. Anything collapsible and lightweight would be harder to clean than something rigid. A collapsible container with a wide mouth? That's a zip lock. Collapsible with a rigid wide mouth? There are some silicone bottles, but they are really heavy.

Does it make sense to have both a cold soaking container and a metal cooking pot?  Enter the bottle pot, such as the Vargo Titanium Bottle Pot HD. If I am going to be boiling water or otherwise cooking in a pot, I bring along my Stanley Adventure stainless steel water bottle (no longer made). Other times I prefer to skip with cooking or cold-soaking altogether, and bring only soft bottles. If I am hunting without a pot, I can cook with sticks.

I'm looking for compact filters that in addition to removing bacteria and viruses, remove chemicals and make yummy tasting water. Carbon and ion exchange resin wear out, so it would be nice if you could refill a cartridge with bulk. In a make believe world that didn't revolve around profits, the most environmentally friendly option would be to take your filter cartridge to the store (like REI), and have them refill your cartridge with fresh media for 2 dollars.

This filter doesn't state what stages it has, but it does say it filters viruses, and “chlorine, chemical, taste and odor removal” (ANSI/NSF 42):
Aquamira Frontier Max 71 grams

In addition to hollow fiber, the following filter contains carbon and ion exchange resin:
Etekcity Water Filter 60 grams

The carbon and ion exchange media can wear out really quickly if the water is high in ions or contaminants. For this reason, it is better to get a separate cartridge for these media. I'll be using the Etekcity Water Filter, and hoping it will last me a couple of weeks. From previous experience filtering some nasty tap water in New Hampshire, I doubt it will.