One thing I've done a few times is to help out just by writing docs for open source projects.
I know it's a drag. I know it's not that much fun. But it massively - MASSIVELY - improves the project's value, especially if it's low on the totem pole.
Lisp has a literary tradition stronger than other languages. See Richard P. Gabriel, or Paul Graham for that matter. Python and Cpp may have polemics, but none as useful as Let Over Lambda.
I know it's a drag. I know it's not that much fun. But it massively - MASSIVELY - improves the project's value, especially if it's low on the totem pole.