The currency section is very nicely done. My own reactions split into the three obvious buckets. 1) Oh, I don't make that mistake! That's an obvious oversimplification. 2) Yeah, having read your counter-example at the end, I'll insist that I pretty much know that one, too. But thanks for the reminder, even though if I weren't skimming so fast, I'd have got it right, too. And, of course the inevitable. 3) Ouch. I had no idea. You got me on that one.