I like this a lot. (From Gartner, found via The Times)
Superficially, it's similar to a chart that I had a massive pop at a couple of weeks ago. I really like this one though, because it's not pretending to be something that it isn't.
That and the names are brilliant. 'Peak of inflated expectations' and 'Trough of disillusionment' conjure up images of a crazy treasure map a la Monkey Island.
You could draw one with the same names and shape for client relationships, from pitch through inflated expectations, almost losing the business and then a few years later actually starting to get good at it. If they haven't fired you by then...