PS3 System Update 4.50: Changing Trophy Privacy Settings (show/hide)

PS3 System Update 4.50 now allows you to hide trophy sets from others provided you do the following:

• Ensure your Trophies are set to ONLINE mode. If they are not, hit Triangle on your Trophy Collection and hit [Online mode]. The option will not be available if your Trophy Collection is in Offline mode
• Go to the Trophy set that you wish to Show/Hide.
• Hit Triangle
• Uncheck the box for [show trophies for this game]
• Hit down
• Hit OK

The "hidden" Trophy Sets will not be grayed-out locally or otherwise, so you'll have to remember which ones you've unchecked.