Probably the only work ever to use the title as a major plot point/punchline (and a damned effective one, at that), Mathews' novel turns the epistolary genre on its head, with a bizarre love story cum treasure hunt, all wrapped into a tight package of slapstick comedy, mystery, history, culture, and linguistic peculiarities.
For those of you unfamiliar with Mathews' work, he's a member of the Oulipo, a group (or groups) of writers, mathematicians, poets, painters, etc., etc. - who both rescue stylistic constraints from the past and create new ones of their own. So you can always expect that their works will be impeccable structured, rich in detail, language play, and erudition. On top of that, at least one of the characters (Twang) is beautifully written, with a wealth of puns and a generous heap of charm.
There are two minor concerns with the novel that forced me to downgrade it to 4 stars, instead of a perfect five. The first is that the big plot twist, while necessary to set up the game of gross misjudgments in the second half of the novel, comes across as a bit contrived. The second is that the style, while often flexible, fascinating, and outright hilarious, is sometimes uneven - there's none of the assuredness in his writing that you'd find in Cigarettes, for example.
Still, a great read, and highly highly recommended. I wish Mathews and the Oulipo gang were more widely read.