I missed a key defect in my Microsoft Zune media player coverage, Zune Sharing. The player admirably supports a bevy of open file formats, including WMA, MP3, AAC, JPG, WMV, MPEG-4, H.264. As we wrote, it doesn't support Apple's proprietary AAC format, so keep your iTunes songs on your iPod or your PC. But it also doesn't support Microsoft's own DRM format, which is marketed under the Plays For Sure banner.

The EFF brings up the very good point that the omission highlights what is bad about DRM.

To repeat, Microsoft's mobile media player won't play Microsoft-secured files. So it's not compatible with Napster 2.0, Rhapsody, Yahoo! Unlimited, Movielink, Cinemanow, and other services. But plenty of other devices are compatible, including those from Archos, Cowon, creative labs, Dell, Denon, D-Link, Gateway, ILO, iriver, JVC, mobiBLU, mpio, Netgear, Omni, Palm, Philips, RaveMP, RCA, Rio, Roku, Samsung, SanDisk, Tite, Toshiba, ZOTAC.