Local author Mo Lotman's new coffee-table book Harvard Square is an illustrated retrospective of Massachusetts's most-opinionated zip code, but in addition to chronicling the visual changes in the square over the last 60 years, Lotman also offers a section on changes that didn't happen. There's the 1969 idea to build Minneapolis-style glass skyways, the 1964 initiative to build a 23-story motel, and a range of apocalyptic ideas for guarding against nuclear destruction. Aptly titled The Un-Square, this closing section makes for fun alternative history — and may make you grateful for the existence of local planning boards. 

The whole book — which opens with John Updike reminiscing about the square he knew as a Harvard freshman in 1950 — is a procrastinator's paradise, with 235 pages of anecdotes, photographs, and trivia. Did you know that in the '50s, Bob Slate's housed a laundry service as well as a stationery store? Me neither.