First things first: Aldiko is not the only app to offer free e-books to Android users. Amazon's Kindle app has been available for a while now, offering access to a wide range of free and paid literature. Overdrive serves up content through a partnership with many public libraries, allowing patrons to virtually borrow books. There are also a number of other e-book readers easily found by searching the Android Market. But many are restricted by proprietary delivery systems and digitally copyrighted content. Aldiko is a different breed.
Have you ever left the house in a hurry, only to realize you need an important document from your desktop PC? If only there was an elf standing by, able to email it to you... TeamViewer is that elf.