We’ve already looked at the Calibre ebook manager and conversion software, which is great if you have a PC, but what if you only have your Kindle with you?
Retroread.com is an online service that allows you to browse through an existing library of EPUB ebooks that have already been converted into Kindle’s MOBI format. Using the Kindle’s “experimental” web browser, you can download books using just your Kindle and get hold of the million-plus classics at books.google.com.
You can also use Retroread as an online converter, however, you do have to sign up for that. No sign-up is needed to browse and download existing e-books in the Retroread library.