Genuinely curious question. How do you guys pull xkcd comics just like that? Do You save interesting comics for future use or do you remember the comic and google it to find it?
"Duty calls" as in "Someone is wrong on the Internet!", I'm fairly sure. Hey, it's that new hot processor, so a fairly memorable number. "Little Bobby Tables" is 327 IIRC; also the CI capacity of an old American V8 engine (a Ford, I think).
"Money" made an impression at the time. I DDG'd "xkcd money" to pull the URL.
Other times I just suspect that there's a relevant xkcd and try some keywords.