The ability to spawn off workers while you're inside of the terminal is a natural part of working in a shell. One way nu could approach this is to be able to create a task that is worked on in the background, as part of a group of tasks.

These tasks could be killed as a group, closed on exit from the shell, etc.

One possible extension to the idea is to use #244 as a way of jumping back into a background task and interacting with its stdin/stdout.

[idea from @wycats]