I haven't tried it but I assume you can download Mobipocket library books to the iRex DR1000S by inputting your Mobi ID. iRex will also be updating the DR1000S to support secure Digital Edition PDFs and ePubs in "quarter 2 of 2009" (read 2010). But thanks to i♥cabbages's excellent INEPT program and Adam's FBReader port, the DR1000S already supports both these formats.