ki4buc,
I use a Tactical Tailor Urban Operator pack. It is really just for day trips, but it has many useful functions. There is a side pocket that will hold a 1L bottle, which zips closed when not needed. The back pocket holds the laptop around town during commute by public transit (other flat items when hiking). A laptop is very important in an urban emergency, since it provides means to communicate with family members, govt agencies, and insurance companies in a time efficient manner. (It also stores family photos and helps if having to look for a job because of being displaced by longer term emergencies.)The front "admin" pocket is a good place for wallet, other pocket items, etc. I keep the bag next to my bed at night, so I can grab it in case of fire, etc. For this "night" duty, I add a stuff sack with a complete change of clothes. When hiking, I remove the town stuff and add my hiking gear that I keep in stuff sacks. Basically, an internal "modular" system.

Spud