The closest thing we've got is Beam, here on Android, which Apple and MS should seriously consider adopting. The only problem is that it does require some hardware support, IIRC.
Before that, the best thing for file sharing was Bump, which was kind of hacky, and required internet as a result, but did work. Sadly, Bump is no more.
As for sharing files with yourself, my answer is typically SFTP, which is excellent, provided it does what you want. It also works well for transferring files at conferences, providing your slides aren't to big to make the roundtrip in good time. A bit hacky, yes, but it works.
Beam is hardware-assisted Bump, essentially. The protocol is radically different, but the UX is the same. Unfortunately, that seems to be android-only.
Before that, the best thing for file sharing was Bump, which was kind of hacky, and required internet as a result, but did work. Sadly, Bump is no more.
As for sharing files with yourself, my answer is typically SFTP, which is excellent, provided it does what you want. It also works well for transferring files at conferences, providing your slides aren't to big to make the roundtrip in good time. A bit hacky, yes, but it works.