Visiting your local library used to be the only way to get a book on loan, but several web sites have launched services that let you rent texts to your heart's content with the click of a mouse. Although some of these sites focus on textbooks for the college student market, they also offer novels, biographies and complete works that can be rented for one month, or several. Bookswim, BooksFree.com and Paperspine offer unlimited rentals on a monthly subscription plan, while Chegg.com and BookRenter.com base fees on the individual books you decide to rent. And in the case that you just can't put that book down, most sites also allow you to purchase your selection at any time in the rental process.