diff --git a/ChangeLog b/ChangeLog
index 5383cff0b..109436461 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2007-06-01  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
 
+	* SoObjects/Appointments/iCalEntityObject+SOGo.m
+	([iCalEntityObject -userIsParticipant:user]): new proxy method
+	that invoked isParticipant on self for each possible email
+	addresses of the user passed as parameter.
+	([iCalEntityObject -userIsOrganizer:user]): same as above.
+
+	* SoObjects/Appointments/iCalEntityObject+SOGo.[hm]: new class
+	extension module.
+
 	* SoObjects/Appointments/SOGoAppointmentObject.m
 	([SOGoAppointmentObject
 	-saveContentString:contentStringbaseVersion:baseVersion]): remove
diff --git a/SoObjects/Appointments/GNUmakefile b/SoObjects/Appointments/GNUmakefile
index c6effab6d..4e3d3255d 100644
--- a/SoObjects/Appointments/GNUmakefile
+++ b/SoObjects/Appointments/GNUmakefile
@@ -11,6 +11,7 @@ Appointments_PRINCIPAL_CLASS = SOGoAppointmentsProduct
 Appointments_OBJC_FILES = \
 	Product.m			\
 	NSArray+Appointments.m		\
+	iCalEntityObject+SOGo.m 	\
 	\
 	SOGoCalendarComponent.m		\
 	SOGoAppointmentObject.m		\
diff --git a/SoObjects/Appointments/iCalEntityObject+SOGo.h b/SoObjects/Appointments/iCalEntityObject+SOGo.h
new file mode 100644
index 000000000..7f8702b9e
--- /dev/null
+++ b/SoObjects/Appointments/iCalEntityObject+SOGo.h
@@ -0,0 +1,35 @@
+/* iCalEntityObject+SOGo.h - this file is part of SOGo
+ *
+ * Copyright (C) 2007 Inverse groupe conseil
+ *
+ * Author: Wolfgang Sourdeau <wsourdeau@inverse.ca>
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This file is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef ICALENTITYOBJECT_SOGO_H
+#define ICALENTITYOBJECT_SOGO_H
+
+#import <NGCards/iCalEntityObject.h>
+
+@interface iCalEntityObject (SOGoExtensions)
+
+- (BOOL) userIsParticipant: (SOGoUser *) user;
+- (BOOL) userIsOrganizer: (SOGoUser *) user;
+
+@end
+
+#endif /* ICALENTITYOBJECT_SOGO_H */
diff --git a/SoObjects/Appointments/iCalEntityObject+SOGo.m b/SoObjects/Appointments/iCalEntityObject+SOGo.m
new file mode 100644
index 000000000..5b100f9a5
--- /dev/null
+++ b/SoObjects/Appointments/iCalEntityObject+SOGo.m
@@ -0,0 +1,70 @@
+/* iCalEntityObject+SOGo.m - this file is part of SOGo
+ *
+ * Copyright (C) 2007 Inverse groupe conseil
+ *
+ * Author: Wolfgang Sourdeau <wsourdeau@inverse.ca>
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This file is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#import <Foundation/NSArray.h>
+#import <Foundation/NSEnumerator.h>
+
+#import <SoObjects/SOGo/SOGoUser.h>
+
+#import "iCalEntityObject+SOGo.h"
+
+@implementation iCalEntityObject (SOGoExtensions)
+
+- (BOOL) userIsParticipant: (SOGoUser *) user
+{
+  NSEnumerator *emails;
+  NSString *currentEmail;
+  BOOL response;
+
+  response = NO;
+
+  emails = [[user allEmails] objectEnumerator];
+  currentEmail = [emails nextObject];
+  while (!response && currentEmail)
+    if ([self isParticipant: currentEmail])
+      response = YES;
+    else
+      currentEmail = [emails nextObject];
+
+  return response;
+}
+
+- (BOOL) userIsOrganizer: (SOGoUser *) user
+{
+  NSEnumerator *emails;
+  NSString *currentEmail;
+  BOOL response;
+
+  response = NO;
+
+  emails = [[user allEmails] objectEnumerator];
+  currentEmail = [emails nextObject];
+  while (!response && currentEmail)
+    if ([self isOrganizer: currentEmail])
+      response = YES;
+    else
+      currentEmail = [emails nextObject];
+
+  return response;
+}
+
+@end