Index: trunk/src/org/openstreetmap/josm/gui/preferences/SourceEditor.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/preferences/SourceEditor.java	(revision 10021)
+++ trunk/src/org/openstreetmap/josm/gui/preferences/SourceEditor.java	(revision 10024)
@@ -136,4 +136,5 @@
         final SourceEntryListCellRenderer listCellRenderer = new SourceEntryListCellRenderer();
         this.lstAvailableSources.setCellRenderer(listCellRenderer);
+        GuiHelper.extendTooltipDelay(lstAvailableSources);
         this.availableSourcesUrl = availableSourcesUrl;
         this.sourceProviders = sourceProviders;
Index: trunk/src/org/openstreetmap/josm/gui/util/GuiHelper.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/util/GuiHelper.java	(revision 10021)
+++ trunk/src/org/openstreetmap/josm/gui/util/GuiHelper.java	(revision 10024)
@@ -24,4 +24,6 @@
 import java.awt.event.HierarchyListener;
 import java.awt.event.KeyEvent;
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
 import java.awt.image.FilteredImageSource;
 import java.lang.reflect.InvocationTargetException;
@@ -43,4 +45,5 @@
 import javax.swing.SwingUtilities;
 import javax.swing.Timer;
+import javax.swing.ToolTipManager;
 import javax.swing.UIManager;
 import javax.swing.plaf.FontUIResource;
@@ -475,3 +478,34 @@
         return e != null && e.getSource() instanceof Component ? SwingUtilities.getWindowAncestor((Component) e.getSource()) : null;
     }
+
+    /**
+     * Extends tooltip dismiss delay to a default value of 1 minute for the given component.
+     * @param c component
+     * @since 10024
+     */
+    public static void extendTooltipDelay(Component c) {
+        extendTooltipDelay(c, 60000);
+    }
+
+    /**
+     * Extends tooltip dismiss delay to the specified value for the given component.
+     * @param c component
+     * @param delay tooltip dismiss delay in milliseconds
+     * @see <a href="http://stackoverflow.com/a/6517902/2257172">http://stackoverflow.com/a/6517902/2257172</a>
+     * @since 10024
+     */
+    public static void extendTooltipDelay(Component c, final int delay) {
+        final int defaultDismissTimeout = ToolTipManager.sharedInstance().getDismissDelay();
+        c.addMouseListener(new MouseAdapter() {
+            @Override
+            public void mouseEntered(MouseEvent me) {
+                ToolTipManager.sharedInstance().setDismissDelay(delay);
+            }
+
+            @Override
+            public void mouseExited(MouseEvent me) {
+                ToolTipManager.sharedInstance().setDismissDelay(defaultDismissTimeout);
+            }
+        });
+    }
 }