Something else I have been using them for is to take advantage of free internet bandwidth. Internet in New Zealand is metered, and a gigabyte can cost something like $2 NZ. It all adds up quickly. So when someone offers free internet, instead of using their limit of 100 MB a day, I can use 300 MB a day with my three devices. I can download a podcast over a couple of days, resuming the download on additional days.
Or I could, if Apple's iTunes downloading wasn't incomprehensibly badly designed or broken. Pause a download? Chances are that it will start downloading from the beginning again when you resume it. Download get interrupted? Chances are that it will start downloading from the beginning again when you resume it. This is basic functionality - I've downloaded iOS updates several times over, again and again, when it happens on the PC iTunes application. Search the internet, people have been complaining about it for years..
I look forward to the day I can replace these devices with something more user friendly.
Edit: And that day may come sooner! I dropped my iPod on the pavement and the screen shattered - replacing the screen costs a good fraction of an Android phone..