I like this scheme, which in my mind is an instance of a meta-rule that's something like "have a definite, small place for things you will need to retrieve quickly".

You can implement this useful system even if you only have a large container (e.g. large purse/bag/backpack) by putting things in subcontainers. Obvious if the large bag is subdivided, but you can subdivide it yourself by using smaller bags.

I recommend using pencil cases (the flexible plastic ones with zips on the top) in larger purses/bags/backpacks. This can make it much faster to find things in your bag.

So, for instance, in my work rucksack I have the following pencil cases:

• clear one with commonly used electronic bits (conference calling earbuds, listening earbuds, USB thumbdrives, laptop-to-projector adapter, phone-to-laptop adapter)
• clear one with less commonly used electronic bits (connectors, laptop remote control, earplugs)
• clear one with videocamera and tripod
• pink skull and crossbones (=medicine): painkillers, plasters, clean hanky, spare contact lenses

Before I adopted this system, getting something out of my bag was a nightmare of jumbled wires and fishing around. Now it's speedy and convenient. Even when there's lots of other stuff in there (e.g. packed lunch, warm clothing, umbrella, power adapters) it's easy to put your hand on the pencil case with the thing you want inside.

Round my part of the world, cheap pencil cases cost about a pound/dollar or two or less (for unbranded ones in large supermarkets), and come in a bewildering variety of colours and finishes. Having a clear mnemonic for the contents really helps - I can find the medicine bag faster than the others. (It has a distinctive texture, too, which helps when my hand's in the bag.) Clear ones are good since you can instantly see the contents.

The same approach works for e.g. travelling with large bags. If space isn't at an absolute premium (e.g. trying to fly carry-on only) I put things in smaller bags inside the big bags I'm carrying. And even when space is very tight, it's still worth it sometimes - e.g. keeping 'documents I will need during the journey' in an easily-identifiable folder to separate them from 'documents I might like to read during the journey'.