The section called "What you're using" gives you a quick over view of all of your applications, allowing you to delete them quickly.
The 'game and application activ ity' section allows you to control which of your Facebook contacts can see your applications. It also controls w ho can see the applications you have used recently. So, w ho do you want to know that you've added a dating application.
Should your w or kmates know you've been using Farmville recently? Lock this privacy setting down using friend filters.
"Facebook tips: Understanding Facebook Application Privacy Issues"