There is a great story on Business Week ( http://www.businessweek.com/the_thread/techbeat/archives/2009/10/googles_scott_h.html ) about Google's "Evaluation Team" ("Eval"), the team which, among other things, measures the performance of Google's search algorithm. In case you were wondering what I did when I was in Google Engineering (back when even I was young), I used to run that team. Of course, that job was much smaller back when I was doing it than Scott's current job (the company itself was also much smaller). Part of my job, perhaps the most important part, was to know where and when Google's search is broken.
The most fun I had in that job was describing what I did to new Googlers. When they asked me what I do, I would say, "My job is to tell my bosses 'Google sucks', and they give me a salary".
The other joke I used to crack about "Eval" is, "Only 'I' can make eval evil". Bad joke, I know, but it made people laugh.