I'll skip over what I'm actively working on because I think this deserves a mention: I'm a hobbyist digital archivist. This is something where
most people can likely make a meaningful and long-lasting impact, that nobody else could if they didn't.
Archiving, for me, is a way of travelling forward in time. Think about "time capsules" and what not.
Here's what I mean by this: If you write a message on a piece of paper, and read it the next day, your message has successfully traveled forward in time by a day. But as the days pass, the message's survival chances diminish greatly.
The goal of archiving is to give information the highest chances possible to travel forward in time, as long as possible. It's hard to evaluate how good our chances are now, but 2000 years from now, if archaeologists find information on our current society, is it more likely to be the piece of paper you wrote, or an archive that was given the best chances of survival?
It's extremely rewarding and it truly is meaningful. Archive anything. Sort and order it, index it, describe it, upload it. Do it for something you work on. The odds for you to archive something that was not done by anyone else are very high.