Eu tenho usado admob sdk e adicionado como jar externo.Em xml eu especifiquei

<code><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
<TextView android:id="@+id/headerfield"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">
<ListView android:id="@+id/list"
    android:layout_width="fill_parent"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">

<com.google.ads.AdView 
    android:id="@+id/ad"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    ads:adSize="BANNER"    
    ads:adUnitId="Publisher Id"
    ads:loadAdOnCreate="true" />    
</LinearLayout>
</code>

Manifesto

<code><activity android:name="com.google.ads.AdActivity"
    android:configChanges="keyboard|keyboardHidden|orientation"/>
</code>

Mas no modo gráfico está me dando um log de erro:

<code>com.google.ads.AdView - the following class could not be instantiated. 
</code>

Dentro do programa está mostrando

Você deve ter AdActivity declarado em AndroidManifest.xml com configChanges.