I often read many books at the same time and often will not read each book to its last page before switching to another book for various reasons. booklife is an interesting web application that helps one manage the books being read.
Jonathan Palardy announced booklife here.
Booklife allows you to add new books by searching Amazon and add books to lists of "heard of", "to buy", "ready", "in progress", "stalled", "done" and so on. You can edit the tag at later time.