--- maemo-mapper-2.3/src/input.c.orig	2007-11-28 20:15:46.000000000 -0200
+++ maemo-mapper-2.3/src/input.c	2008-01-19 19:18:08.000000000 -0200
@@ -492,12 +492,27 @@
 map_cb_motion_notify(GtkWidget *widget, GdkEventMotion *event)
 {
     gint x, y;
+    double lat, lon;
+
     GdkModifierType state;
     printf("%s()\n", __PRETTY_FUNCTION__);
 
+    if(_is_calibrating){
+           MACRO_BANNER_SHOW_INFO(_window, _("Calibrating Map"));
+           printf("Calibrated ");
+           _is_calibrating = FALSE;
+	   screen2unit((gint)(event->x), (gint)(event->y ),
+           x, y);
+           unit2latlon(x, y, lat, lon );
+           LATCALIB = _gps.lat - lat + LATCALIB;
+           LONCALIB = _gps.lon - lon + LONCALIB;
+           _center_mode = CENTER_LEAD;
+           return TRUE; 
+    }
+    
     if(!_mouse_is_down)
         return FALSE;
-
+    
     if(event->is_hint)
         gdk_window_get_pointer(event->window, &x, &y, &state);
     else
@@ -550,6 +565,7 @@
 gboolean
 map_cb_button_release(GtkWidget *widget, GdkEventButton *event)
 {
+    
     printf("%s()\n", __PRETTY_FUNCTION__);
 
     if(!_mouse_is_down)
--- maemo-mapper-2.3/src/data.c.orig	2008-01-12 20:46:01.000000000 -0200
+++ maemo-mapper-2.3/src/data.c	2008-01-19 19:17:54.000000000 -0200
@@ -104,7 +104,7 @@
 gboolean _satdetails_on = FALSE;
 
 gboolean _is_first_time = FALSE;
-
+gboolean _is_calibrating = FALSE;
 
 /** VARIABLES FOR MAINTAINING STATE OF THE CURRENT VIEW. */
 
--- maemo-mapper-2.3/src/data.h.orig	2008-01-12 20:46:01.000000000 -0200
+++ maemo-mapper-2.3/src/data.h	2008-01-19 19:17:47.000000000 -0200
@@ -81,7 +81,8 @@
 extern GpsData _gps;
 extern GpsSatelliteData _gps_sat[12];
 extern gboolean _satdetails_on;
-
+double LATCALIB,LONCALIB;
+extern gboolean _is_calibrating;
 extern gboolean _is_first_time;
 
 
--- maemo-mapper-2.3/src/gps.c.orig	2007-11-28 20:15:46.000000000 -0200
+++ maemo-mapper-2.3/src/gps.c	2008-01-19 19:17:59.000000000 -0200
@@ -145,7 +145,7 @@
         MACRO_PARSE_FLOAT(tmpd, dpoint - 2);
         dpoint[-2] = '\0';
         MACRO_PARSE_INT(tmpi, token);
-        _gps.lat = tmpi + (tmpd * (1.0 / 60.0));
+        _gps.lat = tmpi + (tmpd * (1.0 / 60.0)) + LATCALIB;
     }
 
     /* Parse N or S. */
@@ -163,7 +163,7 @@
         MACRO_PARSE_FLOAT(tmpd, dpoint - 2);
         dpoint[-2] = '\0';
         MACRO_PARSE_INT(tmpi, token);
-        _gps.lon = tmpi + (tmpd * (1.0 / 60.0));
+        _gps.lon = tmpi + (tmpd * (1.0 / 60.0)) + LONCALIB;
     }
 
     /* Parse E or W. */
@@ -900,7 +900,9 @@
 gps_init()
 {
     printf("%s()\n", __PRETTY_FUNCTION__);
-
+    LATCALIB = 0.00000000;
+    LONCALIB = 0.00000000;
+    _is_calibrating = FALSE;
     _gps_init_mutex = g_mutex_new();
 
     /* Fix a stupid PATH bug in libgps. */
--- maemo-mapper-2.3/src/menu.c.orig	2007-11-28 20:15:46.000000000 -0200
+++ maemo-mapper-2.3/src/menu.c	2008-01-19 19:18:13.000000000 -0200
@@ -75,6 +75,9 @@
 static GtkWidget *_menu_poi_categories_item = NULL;
 static GtkWidget *_menu_maps_submenu = NULL;
 static GtkWidget *_menu_maps_mapman_item = NULL;
+static GtkWidget *_menu_maps_mapcalib_item = NULL;
+static GtkWidget *_menu_maps_mapcalibreset_item = NULL;
+
 static GtkWidget *_menu_maps_repoman_item = NULL;
 static GtkWidget *_menu_view_zoom_in_item = NULL;
 static GtkWidget *_menu_view_zoom_out_item = NULL;
@@ -518,7 +521,24 @@
     vprintf("%s(): return TRUE\n", __PRETTY_FUNCTION__);
     return TRUE;
 }
+static gboolean 
+menu_cb_maps_mapcalib(GtkMenuItem *item)
+{
+  _is_calibrating = TRUE;
+
+  MACRO_BANNER_SHOW_INFO(_window, _("Calibrating Map"));
+  return TRUE;
+}
+static gboolean 
+menu_cb_maps_mapcalibreset(GtkMenuItem *item)
+{
+  _is_calibrating = FALSE;
 
+  MACRO_BANNER_SHOW_INFO(_window, _("Calibration Disabled"));
+  LONCALIB = 0.000;
+  LATCALIB = 0.000;
+  return TRUE;
+}
 static gboolean
 menu_cb_maps_auto_download(GtkMenuItem *item)
 {
@@ -1474,8 +1494,17 @@
     gtk_menu_item_set_submenu(GTK_MENU_ITEM(menu_item),
             _menu_maps_submenu = gtk_menu_new());
     gtk_menu_append(_menu_maps_submenu, gtk_separator_menu_item_new());
+
+    gtk_menu_append(_menu_maps_submenu, _menu_maps_mapcalib_item
+            = gtk_menu_item_new_with_label(_("Calibrate Map...")));
+    gtk_menu_append(_menu_maps_submenu, _menu_maps_mapcalibreset_item
+            = gtk_menu_item_new_with_label(_("Calibrate Reset...")));
+    gtk_menu_append(_menu_maps_submenu, gtk_separator_menu_item_new());
+
+
     gtk_menu_append(_menu_maps_submenu, _menu_maps_mapman_item
             = gtk_menu_item_new_with_label(_("Manage Maps...")));
+    
     gtk_menu_append(_menu_maps_submenu, _menu_maps_repoman_item
             = gtk_menu_item_new_with_label(_("Manage Repositories...")));
     gtk_menu_append(_menu_maps_submenu, _menu_maps_auto_download_item
@@ -1714,6 +1743,10 @@
                       G_CALLBACK(menu_cb_maps_repoman), NULL);
     g_signal_connect(G_OBJECT(_menu_maps_mapman_item), "activate",
                       G_CALLBACK(menu_cb_maps_mapman), NULL);
+    g_signal_connect(G_OBJECT(_menu_maps_mapcalib_item), "activate",
+                      G_CALLBACK(menu_cb_maps_mapcalib), NULL);
+    g_signal_connect(G_OBJECT(_menu_maps_mapcalibreset_item), "activate",
+                      G_CALLBACK(menu_cb_maps_mapcalibreset), NULL);
     g_signal_connect(G_OBJECT(_menu_maps_auto_download_item), "toggled",
                       G_CALLBACK(menu_cb_maps_auto_download), NULL);