If i did a software version, here is what i would do is this:
A very opinionated
piece of software that tried to present a specific method of operation.
There would basically be two views:
- Working View
- Maintenance View
In the "Working View" you would see a very clean desktop which tried to reproduce the visual card metaphor. This might be so minimialistic as to restrict view to a stack of cards and then 1-5 chosen cards laid out and displayed very large on screen -- like real size 3x5 inches.
In the Maintenance View, you wouldn't see cards at all, it would be more like a hierarchical note tree or grid, optimized for very quick sorting and searching by various fields, show stats, etc.
That is, the Maintenance View would be designed to do what the physical system can't -- let you find anything quickly, let you look at your past completed cards, show you stats, let you add new cards, edit cards, easily, etc. Not too much worry about visual prettiness here -- in this view its all about power.
And then on the Working View you would want a very minimalistic aesthetically appealing space with very little on it -- just the one or two cards you are currently working on.
And maybe a feature for printing out batches of cards on pre-punched index card stock, and a very quick way to add new cards to be filed later.