For the price of a laptop, one can buy more index cards than lasts a lifecycle, or a lifetime. A buck of index cards occupies the same amount of space as a Blackberry. A 3 x 5 index card holds a calendar, a ticker file, a diagram, a business card, a poem, a phone number, a ground-breaking thought.
An index card still functions after being soaked. Its battery keeps on going and going and going, weightlessly. Its operating system costs a dime and comes with powerful writing and drawing affordances.
A pocket card is tiny. But a hundred thousand index cards fills up a normal size desktop, a room, or even an apartment. Sorting out cards wastes time, more importantly space, the final frontier.
So rewrite and recycle. (An index card contains no heavy metal yet.) Processing cards into the computer onto one's desktop wastes less time than one might fear. All that does not seem worth writing vanishes into oblivion, a better place than the usual limbo-folders of rank-and-file notes.
A card system that relies on order is already too bloated. Better to put ideas to work : when the cards get lighter, add some more notes. A card system that relies on categorization (e.g. by project names) is too complex : if the idea is obvious, the category it belongs to will be manifest.
Hand writing is fast and fun. Quick sorting by hand is playful and helps prepare for a reunion, a presentation, a speech. Hand computing away from the computer, breathing, smiling, and going slowly.