If only you could use e-Ink, and periodically change the text... (That's exactly why one of my forever projects is a mail slot tag I can modify. "NO ADVERTS" -> "NO ADVERBS" and so on, except in local lingo.)
How about "Dave Jones, EEVBlog"? I know, it's no fun at all.
But maybe you could do door signage in e-Ink, and put whatever gags you can think of there? Like a red-black e-Ink with "Danger! Magic Smoke Extraction in Progress"?