In a recent announcement, online retailer Amazon. com said that the shipping of two versions of its third-generation Kindle e-reader will begin on Friday, August 27.

The company also added that the orders placed henceforth will only be shipped by around September 17 because both models are temporarily sold out owing to strong customer demand.

According to the Amazon Web site, both the versions of the new third-generation Kindle e-readers – which were announced on July 28; and have been termed as “Kindle 3s” by some bloggers - will be “smaller, lighter, and faster”; and will boast Wi-Fi-only as well as Wi-Fi + 3G models.

While the “new generation” Wi-Fi-only Kindle sells for $139, the Wi-Fi + 3G models have been priced at $189. Each of the two versions is available in white or graphite.

Going by reports, the “Kindle 3s” are more evolutionary, rather than revolutionary, e-readers from Amazon. The key enhancements that the company has brought to the “Kindle 3s” are smaller and lighter 6-inch devices, featuring a compact design, a notably improved screen, 4GB memory, and two-fold more battery life of up to four weeks with the wireless turned off.

As per the Amazon Web site, the Kindle has been the best-seller item on Amazon. com for the last two years; even though the company has thus far refrained from publicly disclosing the exact sales numbers of the e-reader.