bookr is a free homebrew ebook and .txt file reader it now has support for pdf files as well....

This is really a usefull program for the PSP and it allows you to take your books on the road and it will organize them nicely....

Heres the link to get it: http://sourceforge.net/projects/bookr/

Sadly there is no homepage site....

And to help out getting ebooks try g2p.org

If this has already been posted i apologize