On a clean installation of Eclipse and the Android Development Tools (ADT), and for a new Android project, when trying to edit the strings.xml file, a java.lang.NullPointerException is thrown.

To fix the problem, edit strings.xml directly, bypassing the GUI, by double clicking the file in the Eclipse workbench, then selecting strings.xml from the tab at the bottom. Then, replace the line that reads:

<resources>

with

<resources xmlns:android="http://schemas.android.com/apk/res/android">

In order to use 3G/Internet with an Android phone and a Yoigo SIM card it might be necessary to define a new APN:

Settings > Wireless & networks > Mobile networks > Access Point Names > MENU > New APN

Then enter the following data: