Mattress spaces
In developed countries, people are constantly throwing out lightly-used mattresses[reasons]Most common reasons: ~ Getting a new mattress ~ Moving out ~ In a small percent of cases, bedbugs (should not be donated) that could still be used for something. What if we could dedicate a small amount of space in the city to lay out all those mattresses so that homeless people have somewhere to sleep comfortably?
Considerations
Locations
Indoor or outdoor? Were could this be done? If it's somewhere homeless people already have access to, maybe it's already being done, so no need for this wikipage after all? If it's anywhere else, then political actions are probably necessary to make it happen. In any case, this section needs some examples of potentially suitable locations.
Hygeine
Perfect disinfection isn't viable, but mattresses could at least be left outside to "air out" somewhere sheltered from rain & dirt. Then the mattress could be dusted off and a mattress cover could then be added.
Bedbugs
If a mattress is at the curb on a "moving day" along with a lot of furniture and other things, it probably doesn't have bedbugs. But to secure a supply of safe used mattresses, it's probably best to have some sort of "charity drive" to reach out to the types of people who would be getting rid of used mattresses (i.e. people who are planning to move or buy a new mattress soon).
Labor
Work would include moving mattresses around, cleaning them up, setting them up; also keeping the general space clean.
Volunteers or paid workers? Decentralized community or registered charity?