Crowdsourced attention allocation
This idea is for people who are busy, important, or otherwise have lots of demands on their time.
This person makes their to-do list publicly available online. Others can request this person's time/attention by adding new items on the list. The trick to make this ever-growing to-do list manageable is that others can not only add to the list but also complete tasks on the list. People who complete tasks on the list earn "karma" that they can spend to prioritize other tasks (either tasks they themselves submitted or any tasks they would like to see completed).
People who use such lists can effectively crowdsource the completion and prioritization of their to-do lists. It also has the effect that tasks that can be easily completed by others will be, and the owner of the list is left with more time to focus on tasks that require their particular attention.