Enable Tasks to be in TWO projects

It would be great to have the ability to have one task in two projects. Or a way to link two tasks together so that when you update one it updates the other one. 

For example: We are planning a fundraising campaign with dates that that our communications department needs to be aware of. I would like to have the task, Send Kick off Email, in our fundraising campaign projects AND in our communications calendar project. That way if dates change or if it gets marked completed in one project it will already be updated in the other project.