@ben @dmitri @andypiper presumably this would be a public-only travel intention feed? Seems like building a "coincidence calculator" client on top of ActivityPub location events with future start/end timestamps would be plausible. @mastodon.social@edent already investigated the data publication side https://shkspr.mobi/blog/2024/01/rebuilding-foursquare-for-activitypub-using-openstreetmap/ - makes me want to dust off some old notebook sketches for how I’d implement that algorithm today.