Here's an idea: calling cards that say, "Compliments of [your username]." Players can leave them for other players -- for example, when leaving a karma crate on a dock, or on a ship deck after stealing a Chest of Fortune.
The cards should have a glint so that they are easily seen and, to prevent littering, should either despawn quickly or somehow be limited in number or use.
Many is the time that I wish I could have sneakily left harmless evidence of my presence. Just a small idea.
ObscureBerry
