(Originally posted on Google+, Sep 30 2015.)
So I got myself what has to be the nerdiest bluetooth keyboard in the world: http://sinclair.recreatedzxspectrum.com/
Quite expensive too, for a bluetooth keyboard. But build-wise, it's a perfect replica of the ZX Spectrum we know and love. Feels exactly right and has the correct key labels. Which means that used with a decent emulator, it recreates the feeling of typing on a real Speccy (without resorting to blind hunt-and-peck which is generally the case if you use a PC keyboard).
And after some fiddling with figuring out how to unlock the full bluetooth QWERTY mode as well as the Speccy-specific mapping, I can confirm that it works as advertised as a generic keyboard for Android, iOS or Windows.
I only had to ask myself, "can I think of anyone who's a more suitable target for this product" to realize that I really had to get it.
It's certainly not for fast touch typing, but programming on a Speccy was more like playing chords on a weird instrument. You didn't need to type e.g. "RESTORE", you'd just press a combination of shifts and an S and then on to the next word. I could throw together long lines of Basic way faster than anyone with a Commodore. As a bonus, you could use it as an eraser just by turning it over...
(2018 update: In the end I was pretty disappointed with the unpolished final state of the Android app, and I never really used it for Speccy gaming. On the other hand, I've used it as a keyboard for my PS3 and my Raspberry Pi RetroPi Emulation Station, and that gives me a warm fuzzy - and rubbery - feeling.)