How can I dynamically download and run a javascript script from a javascript console?

Is there a one-liner I could execute in a javascript console to download and execute a javascript script from a remote source?

I was looking to see if there was a nice way to download this script and use it for experimenting interactively on random pages which may not have say, jQuery loaded.

[edit: I'm aware I could dynamically create a script element but is there a nicer way to do this?]