That's odd you should say that, Don Ferro - Because iTunes are in .m4p or AAC format. In fact, I only see a "convert to AAC format" option, and even that doesn't work with protected files. They cannot be converted to MP3's as far as I know, at least not within iTunes. You cannot even play iTunes songs with Napster, and vice versa. (Napster songs are protected WMA files).

iTunes can only be played on an iPod, while Napster's can be played on any MP3 player - except an iPod, I believe. iTunes costs 99c/song while "most" of Napsters songs are available for a flat monthly fee of $9.99/14.95, so I chose the latter (tho I still keep iTunes in case I want to buy e-books or other special content).