There's a guy rides a 20 along the A10 cycleway. Not sure where he goes after, as I've never seen him north of its north end. He's so hard he doesn't bother with air in the tyres, so maybe he rides onto the 70mph dual carriageway that I avoid!
A pair of 20s welded together in various creative ways (including a witch's cauldron with smoke and a push-me- pull-you with one reverse drivetrain) has won prizes at the local Samaritans fancy dress ride a few times. Apparently, they're a good tough mechanical engineering base to build on.