BookWorm is an Android application that allows you to keep track of books you have read and those you intend to read. It is not a book reader. You can enter books by scanning them (product codes), searching for them, or direct form entry. You can rate and comment on each book. Once you have your book list, you can sort and filter it.
BookWorm is available in the Android Market.
Future versions will allow you to import and export data to several popular online book sources (starting with Google Books and Open Library, the two current providers the application uses), and have other social networking features. More Info »
Also, there are many other enhancements planned, check out the issues list and sort by enhancement for a roadmap style view of what's coming.