The Gemstar eBooks and Rocket eBooks were some of the earliest eReader devices.
A company called SoftBook made the first incarnation of these devices, called the SoftBook. There was also a company called NuvoMedia that made a very similar eReader device around the same time, called the Rocket eBook.
In January 2000, both of these companies were purchased by Gemstar. After purchasing and merging those companies, Gemstar released the updated RCA REB 1100 and 1200 model eBook devices. Not long after that, the company discontinued sale of the devices.
These eReaders were only capable of holding about 10 book's worth of text, depending on the size of the book. Like eReaders of today, they had 6-inch screens, but they were much thicker and bulkier. They used a touch-screen that was controlled with a stylus. They had black and white screens that were similar to screens on early PDA devices.
Interestingly, in the beginning the eBook service was provided over the use of a telephone jack. Customers could order eBooks and download them to the device over their dial-up connection.
People who owned these early devices were truly eBook pioneers! You might be able to find one on eBay now if you're lucky. Perhaps someday they will go in an eBook History Museum.