You might try uBook from
http://www.gowerpoint.com/ it is my favorite. It does not read *.lit books, but is does support:
Renders .PDB, .PRC, .TXT, .RTF and .HTML files book-like.
Displays PRC, RTF and HTML images, .JPG, .GIF, .PNG, .WMF (in RTF) or .BMP
Very nce screen rendering and easy to read fonts. I am not associated with them, merely a satisfied customer.
Oh, bye the way, it's free.
V-Man