Recently I ran into an issue that Eclipse didn't want to open XML files that are located in android.jar/res.layout directory. The reason is that android uses Android Common XML Editor. The only thing to do to open binary xml files is to change default XML Editor to Android Binary XML Editor. To do so go to Window -> Preferences -> General -> Editors -> File Associations and change default XML Editor to Android Binary XML Editor.
Most of the time I use Intellij Idea Community Edition for Android development, but recently I had to switch to Eclipse for some reasons. It could be really painful because I really got used to Intellij Idea default key scheme (pdf). But, thankfully, there is simple and elegant solution for this by Santhosh Kumar. Just download the jar file and place it into plugins folder in your eclipse folder. Than restart eclipse. In eclipse go to Window -> Preferences (Windows) or ADT -> Preferences (Mac) than to General -> Keys and in the "Scheme" droplist choose "Intellij Idea" and press apply. That's it! Now you have the default Intellij Idea Keymap in your Eclipse workspace.