Hey, this is funny!
And it educational too. How often does that happen?
The discussion of punctuation was clear, full of good examples, and peppered with historical explanations and comments. I especially appreciated the last part--it's great knowing not only how and why to use commas but where they came from and why they have such complicated, contradictory functions.
I have read complaints that it is about British usage only, with little allowance for American variation, but I did not find that to be the case. Much of the punctuation is the same on both sides of the Atlantic, and when there were variations, Truss commented on them.