What's more, if a friend installs an app, the program will by default be able to see anything you've shared with that friend. To restrict the data available to friends' apps, go to Settings, Privacy Settings and click the Applications link. Click the Settings tab up top, and de-select any check boxes on that page for info you don't want shared. Keep in mind that these settings won't change what the apps that you install can read, only the apps that your friends install.

Your next good move is to make use of a little-known feature that allows you to create a list of friends, then restrict content-sharing to certain lists. For example, you can put all business acquaintances on one list, and restrict photo viewing for those people so they can't see every (potentially embarrassing) photo that you (or they) appear in. Another list, consisting of your closest friends, might be allowed to see everything.

To create a list, click on the Friends link, and under 'Lists' on the left side, click Create. Then, to restrict sharing info with only certain lists, head to Settings, Privacy Settings and click Profile. Select a Profile item's drop-down menu and choose Customize. Then select Some Friends in the resultant pop-up, and enter the name of the friends list you want to choose.