Public spaces contain fewer rubbish bins than ever before (partly because of the perceived need to deny terrorists receptacles in which to hide bombs).
This has led to a phenomenon called Litterplugs, in which people without access to bins find a convenient crevice and shove their litter there.
Today’s invention exploits this tendency by providing locations into which people can cram their refuse legitimately. They would shove eg crisp packets, crushed drinks cans, etc into the top of a gap between two plexiglass screens mounted on a wall.
This would allow inspection of the contents and when full, could be easily cleaned out by allowing one sheet to rotate about one corner fixing (red), dumping the contents into a larger, mobile waste bin.