a federated database of excess resources individuals in a community have on hand and available to other members of the community with a search interface that only provides anonymized results with fuzzy location
integrate it into/build it atop an existing federated identity (say, a mastodon account) and search results could respect blocks, etc (at the cost of increasing the likelihood a persistent individual could de-anonymize results)
also, the looser the concept of "resource" is the better. I should be able to list that I have an unlimited quantity of "food and a chat" available by request to community members and have the opportunity to optionally tie that to a range I am willing to deliver to.