This is a simple implementation of a dropdown view to be used in Android applications.
The files you will need:
/src/com/szugyi/dropdown/view/DropDown.java
/res/layout/view_drop_down.xml
/res/values/attrs.xml
/res/values/colors.xml
You can copy and paste them into your project, or make a library project of this one, by selecting the Properties menu from the context menu of the project folder, then selecting Android and checking in the Is Library checkbox. Do not forget to reference this project as a library project if you choose the second way to use the files.