BERKELEY -- There are no due dates or fines, no alarmed exits or burly security guards -- you can't steal books that are free -- and no admonitions to keep voices at a whisper.
In fact, at the Little Free Libraries, where signs encourage passers-by to "take a book, return a book," talk is encouraged.
"It starts conversations," said Pieter Schouten, who hosts a little library on Dowling Place, along a route he says is popular with folks going from the Mokka Cafe on Telegraph Avenue to Alta Bates Hospital.
"I never thought something so simple could make such a difference to a neighborhood," he said.
Schouten's little library is part of a worldwide network of free libraries that started in 2009, in Hudson, Wis., when Todd Bol built a small replica of a one-room schoolhouse to honor his mother, a teacher.
He mounted the schoolhouse -- actually an elaborate box -- on a stake outside his home where neighbors would pass by, and filled it with books, according to the organization's website.
As the concept grew, the Little Free Library became a nonprofit corporation that encourages building communities through the free exchange of books. There are now more than 10,000 little libraries in 52 countries, the website says.
From afar, the little libraries often look like birdhouses -- or like mailboxes imitating birdhouses -- though there is reportedly one made from an old phone booth in the Rockridge area of Oakland and newspaper articles talk about others made from old suitcases, microwave ovens and even a minifridge.
Typically a Little Free Library holds one- to two-dozen books, though some have shelves that can hold more. Little Free Library sells ready-made libraries and kits for home assembly; they also offer plans people can download free to make their own.
In Schouten's case, his daughter's second-grade class at the Escuela Bilingüe Internacional constructed his library using Little Free Library plans. Schouten bought the library at a school fundraising auction about nine months ago.
Across town, Joe Hellerstein, the steward of the little library near the intersection of Marin Avenue and Santa Barbara Road, decided not to use either the ready-made structures from the Little Free Library or its plans.
He went down to Urban Ore and found an old wooden box that suited the purpose. (The Little Free Library website encourages the use of recycled materials.)
Hellerstein got the idea from the source. He's from Wisconsin and visits annually.
"I saw them there and was charmed," he said. People come by on their daily walks, and the titles are constantly changing, Hellerstein said.
"Occasionally, somebody will dump a technical manual, but mostly it's good stuff," he added.
Even if you build your own container, the Little Free Library website encourages registration, which entails a modest fee and includes little signs with the Little Free Library logo, a charter number and the option to have the registrant's library address plotted on a map, which is available online.
Not all free libraries are part of the network. There's one at Rose Street and Shattuck Avenue and another sporting Christmas lights on Carleton Street near San Pablo Park that appear to be independent. There's a table at Berkeley's Washington Elementary School where children are encouraged to leave and take books. The name "Little Free Library" is trademarked, but the concept, of course, is free to anyone who wants to set up an exchange.
Most of the little libraries in the Berkeley-Albany-El Cerrito area are near residences, but Kathleen Glenn decided to put hers in front of her framing shop on Stockton Avenue in El Cerrito.
It was a birthday gift from her daughter, who, Glenn said, knows how much she values community.
"People love it," Glenn said. "Little kids' books really go fast."
Glenn said she loves holding real books in her hands and sees her little library as contributing to their preservation. "I don't want to see books disappear," she said.
The Little Free Library is at www.littlefreelibrary.com.