The Google Reader team are pleased with themelves, not without reason:

Today we built the 500th version of Reader; over the 5 years that we’ve worked on Reader, that works out to almost two builds a week.

I suspect that’s distinctive, if at all, only in that they are both keeping score and saying so in public.  I heard an Amazon person talk about version 300 or so quite a few years ago.  Closer to home, I remember Tom Steinberg saying the N010 petitions site was on version 3 (or was it 5?) at the end of the first day of live running.

Some of that, of course, is about how you to choose to count things.  But a lot of it isn’t.