A c|net test shows that DRM is computationally expensive and results in a measurable drain on battery life. For Microsoft's WMA 10 DRM on a Creative Zen Vision:M, DRM resulted in 25% less battery life. The iPod and Fairplay only accounted for 8%. Whether it's 8% or 25%, the shortened play time is a feature cost that puts the burden square on the user. You pay for the music and then you get less functionality than you would with uncrippled tracks. Ugh!