I'm looking for the ability to link tasks across boards. For example, we're tracking financials in one board and the individual tasks in another - and would love to be able to link back to the tracked expense.

For example, I track all social deliverables in one list and a have a "stock links" field where I drop links in. I'd love to be able to link the task from the expense list, where's there's proof of purchase, to that production task.