You can Lock the Orkut albums separately. To do this Login to your Orkut account, go to http://www.orkut.com/PrivacySettings.aspx Choose "Choose Individually" in the drop down box of albums. Now all the albums will be listed with a drop down on the left for each. You can choose the settings for each album individually.

This is not a trick, Orkut added this feature and just wanted to inform you about this.

I know this is a great facility, and I like this.