public class Main extends MapActivity {
    private MapView mapa;
    private MapController controlMapa;
    private Button boton;
    private EditText input;
    private String direccion;
    private List <Address> address;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mapa = (MapView)findViewById(R.id.mapa);
        controlMapa = mapa.getController();
        input = (EditText)findViewById(R.id.editText1);
        boton = (Button)findViewById(R.id.button1);

        mapa.setBuiltInZoomControls(true);

        boton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {

            direccion = input.getText().toString();

            if(direccion.equals("")){
                toast("No hay dirección para buscar : (");
            }else{
                toast("Buscando \""+direccion+"\"");
                Geocoder coder = new Geocoder(getApplicationContext());

                try {
                    address = coder.getFromLocationName(direccion, 1);
                    Address location = address.get(0);
                    int lat = (int) (location.getLatitude()*1E6);
                    int lon = (int) (location.getLongitude()*1E6);
                    GeoPoint loc = new GeoPoint(lat,lon);
                    controlMapa.setCenter(loc);
                    controlMapa.setZoom(14);
                } catch (IOException e) {
                    toast("No se ha encontrado la dirección : (");
                }
            }

            // Ocultar el teclado
            InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
                imm.hideSoftInputFromWindow(input.getWindowToken(), 0);
            }
        });
    }

    @Override
    protected boolean isRouteDisplayed(){
        return false;
    }

    public void toast(String mensaje){
        Toast.makeText(getApplicationContext(), mensaje, 1000).show();
    }
}

Manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.buscandomapas"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <uses-library android:name="com.google.android.maps" />
        <activity
            android:name="com.example.buscandomapas.Main"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

    <uses-permission android:name="in.wptrafficanalyzer.locationmodesmapv2.permission.MAPS_RECEIVE"/>
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
</manifest>