Do I need all my keys?

I'm just about to head out for lunch and went to grab my key chain. I've got this really cool key chain from Brookstone that has quick release rings where I can pop off a given key ring very quickly (but I hardly ever use that feature). I thought about how I always take all my keys with me instead of just the one I know I need for the job at hand (e.g., I don't need the key to my storage garage to go to lunch--just my car key). Then I thought about why. For me, it comes down to two reasons:

1. You never know when you might need the others
2. (This one is by far the biggest reason for me) I want to keep them all in one place so I don't lose them.
   

This got me thinking about the differences between the FranklinCovey and GTD time management systems. FranklinCovey was about bringing your whole planner or key chain with you everywhere whereas it seems like the GTD approach is kind of like taking the key along that you need for right now (knowing, of course, that you'll have whatever key you need when you need it from your trusted system).

Imagine if your car door, house, office, PC, etc. were all biometric and you got into what you needed to get into just by being there--without having to carry a key chain for each eventuality (kind of like the world depicted in Minority Report). Now imagine sitting down to your work or home PC and all the tasks you need to do at that particular PC emerge (and only those tasks). Your phone tells you the calls you need to make. You can pick up a shopping list from a kiosk at the front of your local grocer that's connected to the list you keep on your refrigerator when you stop in to get some milk.

Are you comfortable with your system being distributed or do you need to have it on you?