I sometimes come across the situation when two (or more) different people, usually in different teams, set up separate instances of the same task. An example would be the creation of a piece of collateral for an event. The event team might set up a project for the event with a large number of tasks, one of which is to create a flyer. The content team might be independently briefed about the flyer, but not realize or notice there's already a task for it and create another one. If this isn't picked up early I end up with two tasks, each with comments, attachments, working hours, etc. from the respective teams.
I'd like to any easy way to merge two tasks, combining the comment streams, attachments, etc. There would need to be a mechanism for resolving date, status, etc. conflicts during the merge process.