As suggested by Pierre Poulain (one of our ambassadors), we should prepare material to support the organisation of "software archive"-athons during events and conferences (in person or virtual).

This can be very simple: show briefly how "save code now" can be used, then encourage participants to go out and save relevent software they now.
A nice extra twist would be to update existing articles, web pages, documentations, WikiPedia or Wikidata page with the link to the archived version.

As an example, see how I added the link to the archived version in SWH to the Wikipedia page on the now famous inverse square root function as found in Quake III Arena (see https://en.wikipedia.org/wiki/Fast_inverse_square_root#cite_note-quakesrc-10)