I love Pi; I love 2Pi twice as much! (sqrt(2pi) -- don't ask) However, Pi is too math & physics oriented, and doesn't say anything specifically about computer science. So what would be the single number that most computer science people would recognize and acknowledge as being representative of computer science? Some possibilities, just to warm people up: ln(2) ~ .693 (Computer science people only want logs to base 2!) phi ~ 1.618 (One of Knuth's favorite numbers) gamma (Euler's constant) ~ .57722 (related to digital approx to log function) (should this be digital approx to log2 function?!?) Gibb's constant ~ 1.8519 (Inevitable overshoot for digital/square waves) Sierpinski triangle dimension ~ 1.58496 (Visual representation of why recursive algorithms can be efficient!) Any other suggestions?