Thanks for the entries I have received directly, in response to the call for some actually-true metaphor we can use in place of the "throw a frog into a pot of boiling water..." cliche, which is memorable but false. Entries via posts and comments on Matthew Yglesias's and Brian Beutler's sites qualify too.

Winners announced in a couple of days, and then I'll lug a bottle of choice Chinese wine back with me on an upcoming US visit (and will somehow get it to the winner). If you've got another suggestion - for the frog metaphor, I mean, not the prize -- send it now.