Considering my merephone plans... The device will require an SD card to be plugged in!
At the very least I'd need to store an addressbook & chat history there, my design relies on that! Though I'll have plenty of other uses, including storing data for improved text rendering.
So I suppose I'll need an error screen for when it lacks an SD card! I think I'll probably include a QR code there linking to a download page for a disk image with some near-necessary files?