Barnes & Noble's new color Nook is the latest milestone for e-readers -- which first hit the market 20 years ago. Here's a look back.
Sony Data Discman
Launched: September 1991
Launch price: $550
The predecessor to today's e-readers, the Sony Data Discman read audio CDs and CD-ROMs (remember those?). The Discman was primarily pitched as a research device, letting users have access to encyclopedias and other digitized reference books on the go.
"The latest portable computers are marvels of miniaturisation, packing the magnetic disc and memory capacity of a desktop brute into an A4-sized slab. They can carry all the office databases," a New Scientist reviewer wrote in 1992.
E-books available at the time included Compton's Concise Encylopedia, Wellness Encyclopedia and Passport's World Travel Translator. The King James Bible and a year-in-review disc of USA Today were also available.
NEXT: Ahead of their time