Stanza is an early entrant into this market, featuring a clean, well-organized interface that's designed for reading all kinds of digital publications, including electronic books, newspapers, PDFs, and general web content. It's elegant because it's been designed specifically for the Mac, and puts an emphasis on highlighting hyphenation, columns, automatic text scrolling and user-friendly page and chapter navigation.
This is done to make reading long texts easier on the eye and brain, which can soon get tired from reading lengthy data on an electronic screen. Stanza supports HTML, PDF, Microsoft Word, and Rich Text Format reading, as well as all the major eBook standards. It's also a very open reader - developers can add new formats to the programs API meaning it will always be able to handle the latest releases.
Stanza is a fully functional reader that's a little bloated in places but it could be well positioned to be one of the front runners when eBooks and digital publishing really takes off.