I am planning to institute this as a gifted item for all players of 3rd level or higher, especially for one shot games.
All players have a small, unadorned Pack of Useful Items when examined has virtually no weight or items within. Any item from the players handbook of worth less than 20 gp, less than 1 foot in diameter and 10 pounds in weight and are considered common and non-magical to their home location is assumed to be in their pack. It is a standard action to reach into their pack to grab any single item a player will want. The owner can retrieve any specific item 2 times a day (or 4 for small items) but no more than 10 items total can be retrieved on any given day. These packs will only work for their owner or an ally, if stolen, they cease functioning after 24 hours. Items that are not listed in the players handbook are not available until added by the character. Some items, the DM can rule, are too rare to be added to the pack. Items such as cloaks, which can be folded into a one foot diameter, can be summoned in this way.
These items are assumed to be payments for previous missions completed for churches or magic users. Individuals with oaths of poverty or other restrictions with wealth may not have one of these crafted items. These gifts are meant to assist the character in completing missions, not to make wealth, trying to summon items just to sell will make the pack go inert.
Aura faint (gray or rust) or moderate (tan) conjuration; CL 7th
Requirements Craft Wondrous Item, secret chest; Cost 1,250 gp