I've been playing with the notion of equipment and treasure cards for the players for some time now. It seems darned handy for four reasons:
First off the players can have all the information about the item all in one spot and accurately recorded. One can record saves for the item and even things like freshness dates for rations and potions, all the stuff that players would usually never bother keeping track of or simply don't have ready access to in one place.
Secondly it makes encumbrance relatively easy...count the cards or tally the weight on the cards.
Easy book keeping, if you have the card you have the item or the treasure, don't have the card you don't' have it.
Lastly a DM can confirm the item card is actually on hand as it has physical presence, no "magical" appearances on character-sheets and no forgetting one is hauling around a ladder or other large item.
Secret and incomplete info has to be kept secret from the player and tracked by the DM, sure this is the normal situation but it does reduce the true utility of keeping cards.
A bunch of cards can be hard to keep track of physically and a person losing their cards in the real world loses them in the game world.
A DM would likely have to invest in some card holders to keep track of all the cards.
Big parties with a number of henchmen,hirelings, and pack animals are going tot need a lot of cards.
This method does introduce an interesting chance to alter play style. Instead of a DM reading a long list of items found after a good haul the DM can simply drop the cards on the tabel and have the players paw through them and discover what the treasure is, player actions will slow down play not a reading by the DM.
It may make sense to contain the contents of a pouch or chest in an envelope.
Maybe wrap the items held and carried by a foe in a rubber-band.
So any good ideas or criticisms against homemade equipment and treasure cards?