It's time to set your reading free. Google eBooks is all about choice, so you can use any device you own to read any book, anywhere. http://books.google.com/ebooks

"Lucidor provides functionality to: - Read EPUB e-books. - Organize a collection of e-books in a local bookcase. - Search for and download e-books from the internet - Convert web feeds into e-books."

"Your Mac's default PDF reader, Preview, does let you add sticky notes to pages, but Skim throws highlighting and circling into the mix, giving you more note-taking options. In addition, you can see all of your notes in outline form and jump to their locations, making this a great tool for marking up PDFs. Your notes are saved in the PDF but will only be read by Skim, meaning you can get a clean version back at any time by just opening the file with Preview. Skim is free, requires Mac OS X."