Index: src/java/org/apache/poi/ss/usermodel/Workbook.java
===================================================================
--- src/java/org/apache/poi/ss/usermodel/Workbook.java	(revision 1696016)
+++ src/java/org/apache/poi/ss/usermodel/Workbook.java	(working copy)
@@ -20,10 +20,12 @@
 import java.io.Closeable;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.util.Iterator;
 import java.util.List;
 
 import org.apache.poi.ss.formula.udf.UDFFinder;
 import org.apache.poi.ss.usermodel.Row.MissingCellPolicy;
+import org.apache.poi.ss.usermodel.Sheet;
 import org.apache.poi.ss.util.CellRangeAddress;
 
 /**
@@ -31,7 +33,7 @@
  * will construct whether they are reading or writing a workbook.  It is also the
  * top level object for creating new sheets/etc.
  */
-public interface Workbook extends Closeable {
+public interface Workbook extends Closeable, Iterable<Sheet> {
 
     /** Extended windows meta file */
     public static final int PICTURE_TYPE_EMF = 2;
@@ -360,6 +362,16 @@
     void close() throws IOException;
     
     /**
+     * Allows foreach loops:
+     * <pre><code>
+     * for(Sheet sheet : wb ) {
+     *
+     * }
+     * </code></pre>
+     */
+    Iterator<Sheet> iterator();
+ 
+    /**
      * @return the total number of defined names in this workbook
      */
     int getNumberOfNames();