So this (there's a Wikipedia article) came to my attention a little while ago, and I thought it kind of sad that there didn't appear to be a system that demonstrated the correct use of the 418 error code. Using an old netbook, a tube of industrial sealant, several lines of python, and a teapot from a local charity shop - I put a demo together.
Yes, as a matter of fact, this is a netbook glued to a teapot. Nice teapot too, it's a Denby.
Test 1: can make a decent cup of tea.
Test 2: can pour said cup of tea.
This is the shelf it lives on in my office (using the ethernet connection at the moment because its wireless reliability isn't great). You can test it if you like - the address is http://126.96.36.199/.
Thank you to Laurence O'Toole for photography and proofreading.