If you bought an e-book reader because you like to keep on the cutting edge of technology, chances are you'd also like science fiction. Science fiction is all about changing the world by using technology, some of it so far beyond the average lives of most people that it almost seems like magic. Because science fiction readers have a predilection for new technology like e-book readers, there are plenty of science fiction e-books out there to choose from. Here's an overview and some suggestions.
A lot of classic sci-fi books by authors like Isaac Asimov, Robert Heinlein, Ben Bova, and Arthur C. Clarke are available for free on Google Books. However, much their work was written in the 1940s to 1970s, which can make it seem outdated to modern people for whom modern amenities are a reality. While older science fiction tends to focus on faraway worlds, colonization, and encounters with alien races, the most popular new science fiction books today focus on alternate histories and how technology will affect us in the near future. Newer sci-fi authors who are popular include Michael Crichton, Orson Scott Card, and Alastair Reynolds.
Science fiction for adults tends to focus more on the technology or on a broader socio-political view of its effect on people, but teens prefer books with a narrower focus that follow one teen or a group of teens through life changing events. Authors like Scott Westerfeld, Suzanne Collins, Kenneth Oppel, and Cory Doctorow are making lots of money off teens and their parents these days, but there are also some adult books, like Orson Scott Card's Ender's Game and Douglas Adams' Hitchhiker's Guide to the Galaxy that teens like as well.
While sci-fi for young adults focuses on the character's personal difficulties, younger readers like more action in their reading diet. Science fiction for kids tends to be action packed yet relatable, and often stars kids from the current time period who are pulled out of their comfortable circumstances and confronted with time travels. Current popular authors include Margaret Peterson Haddix, Bruce Coville, Neil Shusterman and Jeanne DuPrau but there are some kid-centric works by famous names like Robert Heinlein and Ray Bradbury out there as well.
E-publishing has made it possible to reduce the overhead on producing a science fiction periodical, so online or e-book sci-fi magazines have flourished. You can download the latest copy of periodicals like Asimov's, Analog, On-Spec, Lightspeed, and Fantasy and Science Fiction to read and check out some short stories while you're available. Short stories are great because they don't require as much of a time investment as a novel does and a lot of periodicals are available for free online.