This has been fixed upstream in bzr. The new behaviour is that from now that in case of a permission error, images will be saved on desktop instead.

$ bzr diff
=== modified file 'phatch/actions/save.py'
--- phatch/actions/save.py	2009-04-14 22:29:45 +0000
+++ phatch/actions/save.py	2009-05-25 16:38:11 +0000
@@ -24,6 +24,11 @@
 from core.translation import _t,new
 from imtools import get_quality, get_size
 
+from core.lib.desktop import DESKTOP_FOLDER, USER_FOLDER
+if DESKTOP_FOLDER == USER_FOLDER:
+    DESKTOP_FOLDER  = os.path.expanduser('~/phatch')
+
+
 JPG             = ['jpg','jpeg','jpe']
 PNG             = ['png']
 TYPE            = '<%s>'%_t('type')
@@ -72,7 +77,17 @@
             dpi     = self.get_field('Resolution',info)
             #filename
             if setting('create_missing_folders'):
-                self.ensure_path(folder)
+                try:
+                    self.ensure_path(folder)
+                except OSError, message:
+                    base = os.path.basename(filename)
+                    photo.log += 'Could not save "%s" in "%s":\n%s\n'\
+                        %(base,folder,message)
+                    photo.log += 'Will try to save in "%s" instead.\n'\
+                        %DESKTOP_FOLDER
+                    self.ensure_path(DESKTOP_FOLDER)
+                    filename    = os.path.join(DESKTOP_FOLDER,base)
+
             #construct options
             options = {'dpi' : (dpi,dpi)}
             if self.is_type(typ,PNG):

=== added file 'phatch/core/lib/desktop.py'
--- phatch/core/lib/desktop.py	1970-01-01 00:00:00 +0000
+++ phatch/core/lib/desktop.py	2009-05-25 16:10:46 +0000
@@ -0,0 +1,47 @@
+# Copyright (C) 2007-2008 www.stani.be
+#
+# This program 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 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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.  If not, see http://www.gnu.org/licenses/
+
+"""Cross platform library to locate the desktop folder."""
+
+import os
+import re
+import sys
+
+USER_FOLDER = os.path.expanduser('~')
+
+if sys.platform.startswith('win'):
+    # Windows
+    from win32com.shell import shell, shellcon
+    DESKTOP_FOLDER = shell.SHGetFolderPath(0, shellcon.CSIDL_DESKTOP,
+        None, 0)
+elif sys.platform.startswith('darwin'):
+    # Mac: verify this!
+    DESKTOP_FOLDER  = os.path.expanduser('~/Desktop')
+else:
+    # Linux
+    user_dirs  = os.path.expanduser('~/.config/user-dirs.dirs')
+    if os.path.exists(user_dirs):
+        DESKTOP_FOLDER = os.path.expanduser(
+            re.search('XDG_DESKTOP_DIR="(.*?)"',open(user_dirs).read())\
+                .group(1).replace('$HOME','~'))
+    else:
+        DESKTOP_FOLDER  = os.path.expanduser('~/Desktop')
+    del user_dirs
+    
+if not os.path.isdir(DESKTOP_FOLDER):
+    DESKTOP_FOLDER  = USER_FOLDER
+    
+if __name__ == '__main__':
+    sys.stdout.write('Your desktop is: %s\n'%DESKTOP_FOLDER)

$ bzr commit -m "save batched images on the desktop in case of a permission error"
Committing to: /home/stani/sync/python/phatch/trunk/                           
modified phatch/actions/save.py                                                
added phatch/core/lib/desktop.py                                               
Committed revision 587.