My suggestion for XKCD after getting mauled in today's exam:
Click...Click Click....Click...`Ok, now we do the measurement'. [open] MMMEOW!! [wild mutated half-dead shriek] [lightning-fast paw slash] [deathly silence]
Alt text: Today's Geiger counters don't make as much noise, and I will defend to death my claim that the exam is as probabilistic as the experiment (if not more).
Before I forget, the best 'All the best' line must be Pota's GTalk status yesterday: 'Tomorrow, may you all be curiosity personified!'. Why? Because curiosity killed the CAT! :P
The title is the core transformation relation of this jaw-droppingly amazing idea called Arnold's cat map.
Update: I found this lovely, lovely cartoon here :D