Libraries are changing. Once known as home away from home for researchers, scientists, and procrastinating students, today's book depositories are currying favor with movie renters, and taking business from Blockbuster (NYSE:BBI) in the process.

Statistics from the Institute of Museum and Library Services (IMLS) speak to the trend. During 2007, the last fiscal year for which the IMLS has data, staff-specific (i.e., research) requests fell slightly. Visits and available material rose over the same period.

What sort of material, you ask? Audio led the library content rally, up 8%. Video collections grew by 6%. To access all this data and more, libraries increased their number of available Internet terminals by 6%, the IMLS report says.

Color me unsurprised. Libraries are bidding to remain relevant in an increasingly digital world. Stocking video and a healthy dose of free Wi-Fi transforms the best of them into a surprisingly effective Netflix (NASDAQ:NFLX) and Redbox alternative.

But, again, the library is a lot more than a replacement for your local DVD rental hub. Here are three ways your library card can help you add wealth.

1. Free investing research
Each time I visit my local library, I see at least one enterprising investor pulling research from the Value Line (NASDAQ:VALU) reports collected on a shelf near the reference desk. Books from Standard & Poor's and Morningstar (NASDAQ:MORN) are stacked just below. That's thousands of dollars' worth of insight positioned less than 10 feet from a nickel- and dime-eating copy machine. I tear up just thinking about the savings.

2. Free shopping research
Walk around the same desk at my local and you'll find two neatly arranged shelves with car pricing guides from Consumer Reports. This is the sort of intelligence that makes shopping at the local Toyota (NYSE:TM) dealership enjoyable rather than terrifying.

3. Freely available books from and about stock-picking masters
You know the texts. Roger Lowenstein's Buffett: The Making of An American Capitalist. Peter Lynch's One Up On Wall Street. Joel Greenblatt's You Can Be a Stock Market Genius. All of them are available at your better libraries, and they'll cost you nothing to borrow. Unless, that is, you're lazy and refuse to return their copies on time. Then they'll cost you $0.30 (or more if you're really late) to borrow.

Now it's your turn to weigh in. How do you get value from your local library? What ideas did I miss? Make your voice heard using the comments box below.