One thing I've wanted for years is a small, pocket-sized and battery operated blob of storage with a well-defined API, where all of my data lives. Not the cloud

One thing I've wanted for years is a small, pocket-sized and battery operated blob of storage with a well-defined API, where all of my data lives. Not the cloud, because no, thank you; and not an external drive. I want something that my phone, my laptop, my TV, my workstation can use as a canonical data storage location for everything in my life. Ideally this would have a fast radio, so I could just leave it in my bag while I'm walking around listening to music on my phone; and a high-speed physical connection so I can plug it in if necessary.