Selecting titles for off-site storage in a large library is sometimes a trip through the history of fads and passions. Years ago, I sent off a number of titles on atheism from the 1960s, thinking that subject probably wouldn't be a craze again. Less than a decade later came Dawkins et al., so I'm definitely no seer.
However, I do have a proposal for the shortest-lived genre in book history: A Guide to [Whatever Subject] on the Internet. Ten or fifteen years ago this was a hot genre, and now the notion of using a book as a guide to websites just seems archaic.
I vote for Y2K survival guides.
Oh, that's very good! I think I'll change my vote.
I still have my copy of the first edition of Ed Krol's Whole Internet User's Guide and Catalog. It's maybe 200 pages, and the chapter on the Web is the shortest one. (The book predates Mosaic, if memory serves.)
I've kept it largely for nostalgia purposes, though it's fun sometimes to show students how different things used to be, and how recently. (Explaining why they were called floppy disks, when none of the students had ever seen one that flopped, was another notable moment. Of course, at this point none of them have seen disks of any kind...)