A good scenario is building a backup server/nas solution that you can put in a little cubby at your friends place. There's trust involved that you're not using their internet to hack the government, and you have to be mindful of their bandwidth/power costs. So not a rackmount server or even a tower, but something much smaller and very appliance looking. A nuc sitting atop a wd passport or their "my book".

If it provides them a benefit like an in-house plex server, even better.