When The Worst-Case Scenario Survival Handbook first came out, in 1999, it succeeded as clever reading material to keep in the loo. But with the disasters of the intervening years, the book has come to feel less like a novelty and more like a crucial reference work. That's also true of the latest installment in the series, The Worst-Case Scenario: Extreme Edition (Chronicle Books, $15). Authors Joshua Piven and David Borgenicht have devoted one section to adventure athletes, giving instructions on how to survive a street luge wreck and, while surfing, a two-wave hold-down. If you're cool enough to keep all the instructions straight when a crisis hits--stay on the board when your street luge goes out of control, but bail on your surfboard--your chances of survival are that much better.