FILLING A BOOK BAG with a course-load of college textbooks will not only weigh on a student's shoulders, but also their wallet.

On average, college students shelled out $900 a semester for textbooks, according to a 2005 General Accounting Office report. It's just as bad today, says Nicole Allen, textbooks program director for the Student Public Interest Research Groups, a consumer advocate. Students can pay $200 or more for a single science book. College-customized texts (where schools receive a portion of the book's sales from the publisher) only exacerbate the problem by limiting students' ability to sell used copies, says Edgar Dworsky, founder of ConsumerWorld.org, a consumer advocate.

The situation is so bad that Congress has stepped in. On Thursday, it passed the Higher Education Opportunity Act. Among other provisions, the bill requires publishers to share pricing information with professors and forces them to unbundle packages of textbooks and supplementary materials so students can buy only items they need. "It's a critical step," says Allen. "Textbooks really can be the difference between affording higher education and dropping out."

Government intervention isn't the only way cash-strapped students can better their odds of affording their textbooks. Here are some other ways students can save:

Electronic Textbooks

Ditch the heavy hardcover for an electronic book, and save as much as 50%, says Dworsky. In May, six of the biggest textbook publishers, including

Pearson

McGraw-Hill Education

, which sells subscriptions to digital copies of textbooks and other course materials. A 180-day subscription to "Earth Science" (12th Edition), for example, costs $56.67, or 50% less than the print version.

Cengage Learning and Springer, as well as sites like CafeScribe.com to compare prices. Also, ask the college bookstore if they offer electronic books. At the University of Dayton in Ohio, students pay $41 for electronic access to "Making Sense of Movies," saving 41% off a new $70 text.

There are some downsides to electronic texts, however. Unlike their paper counterparts, they can't be returned. Also, subscriptions limit access to a semester or two and copyrights typically prevent printing more than a few pages.

Price Comparison Sites

You can buy almost anything used online these days and textbooks are no exception.

To find the best deals, check textbook-specific price comparison search engines, such as Bigwords.com, CheapestTextbooks.com and Booksprice.com.

Hunting for "Ten Essential Texts in the Philosophy of Religion" (regularly $54.95 new) through CheapestTextbooks.com turned up listings at eight online retailers. The cheapest: $4.21 for a used copy at Half.com (plus $3.49 shipping). Overall, that's a savings of 86%.

Textbook Rentals

Once finals are over, the first stop most students make is at the bookstore, where they hope to sell their books and recoup some cash.

the store needs the text for the next semester, then they'll be lucky to get 50% of their money back.

Web-based textbook rental services, such as Chegg.com, BookRenter.com and CampusBookRentals.com, offer a lot more certainty. Using these services, students pay as little as a third of a book's price to borrow it for a set period usually a semester, says Charles Schmidt, a spokesman for the National Association of College Stores. (More than 60 of NACS's member campus stores have their own textbook rental programs.) Chegg.com, for example, mails a copy of "Compact Bedford Introduction to Literature" for $26.88 a semester. That's a savings of 59% off the price of the new version.

One warning: Renting isn't always cheaper than buying a used text, cautions Schmidt. Many rented texts don't include the supplementary materials like CDs or workbooks. Also, these services typically require books be kept in good condition. Play fast and loose with a highlighter, and you could end up forking over the full purchase price.

Subsidized and Open-Source Textbooks

Believe it or not, it's possible to legally download textbooks for free thanks to a handful of new sites and services:

• Freeload Press

• Project Gutenberg

  Barnes & Noble

• Retailers Back Big Back-to-School Sales

• Buying a Refurbished Computer

• The College Tax Breaks Superpage

The biggest pitfall to free texts right now is a lack of selection. The sites are worth a look, but don't bank on finding all the books on your required reading list just yet.

Also see: