Recent versions of the Sony Reader support the "ePub" format natively, which Stanza exports to. For older versions of the Sony reader (e.g., the PRS500 and PRS505), you many need to download a firmware update from http://esupport.sony.com in order to be able to read ePub books. For more details, see http://ebooks.custhelp.com/app/answers/detail/a_id/138.