I'm curious to hear other's thoughts on they think would be useful.
Please don't hold back ideas! There's very little harm positing silly or unlikely ideas, but there is some potential value (perhaps more than you realize).
Inspired in part by calebo's comment here
After competing in multiple hackathons, I've found that they rarely produce useful work. It's actually quite a bit of work to extract and formalize problems (from organizations). I feel like around EA, I'm not sure how many problems there are suitable to hackathons.
That said, they can be good for networking / experimenting with working with different groups. I'm happy I went through the hackathons I did, but more for skill building than direct output.
I think overall I'd expect them to be a decent use of a weekend, but would expect the output to be similar to that of other hackathons (i.e. not that much, so just expect that). ~2 days isn't that much, both in costs and expected benefits.