Inspired by economical lolcats, I guess we should have some rationality lolcats. Here are a few quick ideas:

Two big cats next to each other, a third smaller cat in front of them or hiding somewhere aside. "Consider the third alternative"

One cat standing on hind legs, other cat crouching. "If P(H|E) > P(H) ... then P(H|~E) < P(H)"

Cat examining a computer mouse. "Iz mouse 'by definishun' ... still can't eat"

Cat ripping apart paper boxes. "Stop compartmentalizing"

Cat ripping apart a map. "The map is not the territory"

Cat riding a vacuum cleaner ... something about Friendly AI.

Kittens riding a dog. "Burdensome details"

Cat looking suspiciously at a whirlpool in a bathtub. "Resist the affective spiral"

Or simply a picture of some smart cat (cat with glasses?) and some applause-light texts, like "All your Bayes are belong to us"

I am not sure what is the proper procedure for creating these; specifically whether there is some good source of legally available cat images. What is the correct font to use, and whether there are some tools for conveniently adding texts to pictures. Anyone has experience with this?