Since when have these been around? Also, can you share some details on how the Google search easter egg infrastructure works? I've always found these very interesting. They kind of give a human touch to what sometimes feel like "cold" search result pages.
Early 2012. I forget the exact date - I started them as a demo in I think Dec 2011 and then they sat around on my workstation unchanged for a couple months, so I think they went out around Feb 2012.
I can't share technical details, sorry.
For those who didn't catch it, the search returns "About 0b111001101100101000001000000 results (0.18 seconds)".