There is such a thing as municipal librarian machismo. The literary blogger Maud Newton received a marvellous blast of it a few years ago, after some snippy comments about New York public libraries. Those libraries, a friend wrote to her, were not just for readers of her blog:

"No, my library is for the 40-something woman who is trying to divorce her drunk of a husband and for the secretaries spinning their wheels on the subway holding pace on their life with a page turner and dreaming of a husband like the one in her pink-covered novel.

"My library is for three-year-olds who have never held a book before and reluctant readers whose window for real literacy is open for a matter of months; it is for the religious freak and the politically disenfranchised. My library is for the homeless and the millionaire both and a place where each get exactly the same focused, personal service."

Scott Douglas is, from this perspective, a classic example of a real librarian. The patrons he deals with at two branch libraries in Anaheim, California, are unliterary enough to furnish him with an entire chapter on death threats. (Although, after reference research, he discovers that no one who has threatened to kill their local librarian has ever yet gone through with it.)

When his first branch is closed for refurbishment, a young teenager who calls in to reminisce still remembers his performances at story time.

He is also an enlightening guide to the changes in local libraries over the past decade and a bit. While some of his observations are California-specific ("I think it's fair to say that if you take the bus to the library there's an 85 per cent chance you're clinically crazy and a danger to society"), most will draw a smile - or a yelp of rage - from any holder of a council library card.

The second chapter of this loosely structured book concerns "the Day of the Gateway"; that is, the day that 12 cardboard boxes arrived from Gateway computers, ready to change libraries for ever.

Douglas is at this point a mere library page, as junior as it gets, but the shift in favour of the young, computer-literate male ("We men need to band together," a fellow librarian tells him, "Sometimes I feel these women are conspiring") helps sharpen his sense of vocation.

Computers are a constant presence in the stories that follow. The eccentric library users Douglas celebrates and mocks are much the same as they would have been 25 years ago: teenagers, crotchety old people ("seniors", in his American service-speak), the homeless, the mentally unwell.

But where once a librarian's campfire tales might have concerned the things that people leave under the front flap, here it's the guy who tries to put the print card in the disk drive, the teenagers who hacked the time-limit program, what you do when someone asks for help printing out porn, and the ructions when they banned MySpace.

Eating in the library provides another sub-plot: first popcorn on Saturday (it brings children, but also mice), then fast-food vouchers as a way to promote reading (Douglas slips extras to the threadbare and hungry), then vending machines.

Douglas may waver - can't there be something at least a little healthy in those vending machines? - but finds he can bring himself round to anything that will increase library use.

He sees his story as that of someone who began thinking that libraries were about books, and has learned that, like Soylent Green, jails, churches, etc, what they're really made of is people.

His case for modernisation never rises to the rhetorical heights attained by Maud Newton's friend, because his is a cooler sort of librarian machismo.

Parts of this book were originally published on the website of the literary magazine McSweeney's, and it retains that site's fake-naive comic tone, adding further design whimsy (lots of footnotes, digressions "for filing" set in ITC American Typewriter) and touches of real naivety.

That does not mean Douglas is any less confident of the need for change: libraries must serve food, he states in his afterword, because they have to compete with bookstores.

"I've often asked fellow librarians how long before libraries start to realise the modern library isn't a monopoly, that competition is fierce, and that they have to run the building as such?"

This is sensible. But I'd be happier if there were more talk of libraries competing with bookstores on range of books.