Mohegan 6 0.1
A New Wave lock dialog inspiration
1. Unpack files to /usr/share/gnome-screensaver/
(only the folder Mohegan-images and the files : lock-dialog-mohegan.glade, lock-dialog-mohegan.gtkrc)
2. Open gconf-editor (Alt+F2, type 'gconf-editor' and press enter), change the entry /apps/gnome-screensaver/lock_dialog_theme from 'default' to 'mohegan'
To enjoy this theme fully I recommend using a picture of your choice. You could change your current one by going to System > Preference > About Me and click on the button besides your name.
If you want to get back you old theme you should do step 2 in reverse: replace 'mohegan' with 'default'.