In your android phone are many beautiful icons.Here is the list:http://developer.android.com/reference/android/R.drawable.html and here is more http://developer.android.com/design/downloads/index.html
- in recourses android:icon="@android:drawable/<name of your element>"
- in java code android.R.drawable.<name of your element>
But be aware:
Warning: Because these resources can change between platform versions, you should not reference these icons using the Android platform resource IDs (i.e. menu icons under android.R.drawable).