Wow. This book has revolutionized what I do on long walks. I used to try to identify plants in people's yards, think about what it would be like to live in their house... now I just criticize their pruning techniques and bemoan the terrible treatment of their shrubs. It's very fun.
This is a book that really should be read before attempting to plant, rather than when considering pruning. Cass Turnbull founded Plant Amnesty, and believes that pruning is something that ideally one would do very little of, if planting has been planned well. Makes me a little gun-shy in regard to our own garden, but wow, can I identify badly-headed or unwisely topped trees in other people's!