Shaking the HTC EVO 4G can already be used for taking screenshots or uninstalling apps, so now let's make it do something else. How about giving the phone a little shake to skip to the next song you're listening to with many of the most popular music players available for Android?
The appropriately named Shake2PlayNext lets you do just that.
Just launch the app to start the service and play your music using the stock Android or HTC Sense music players, MortPlayer, MixZing, Meridian, doubleTwist, Rhapsody, Last.fm, Astro, or the ever-popular Cubed. Whether you're using the app itself or its widget, just give the EVO a little shake (sensitivity is adjustable) to skip to and start playing the next track. You can enable the service to work with more than one music player at a time, but it's better to select just one from the settings menu to keep the pop-up notifications relevant.
Two caveats: 1) Shake2PlayNext will hit your battery pretty hard so make sure you turn it off when you're not using it and 2) although it's supposed to be fixed in Froyo, shaking the EVO while the screen is off/locked may result in no action.
The latter issue definitely limits this app's usefulness since most people listen to music with the screen off, but it's really useful when you're using the EVO and listening to music in the background. Apps are supposed to be able to receive accelorometer events when the screen is off/locked in Froyo, as I mentioned above, so this may just be a ROM issue. I'm using SteelROM RevG on my rooted EVO (3.29.651.5) and Shake2PlayNext does nothing when the screen off. I use it a lot when the screen in on, though, and I love it. Your experience may vary.