Recent Items is a great way to quickly open what you want. (Some apps have a similar feature called Open Recent, which is often found in the app's File menu.) The list of Recent Items changes over time, and to make the Recent Items list more useful, you can set the number of apps, files, and servers that appear on the list. Here's how to customize the setting in Lion.

Click on the Apple menu and select System Preferences. Find the General icon; it's the first one listed, under the Personal heading. Click on general, and a window with four sections will appear.

In the third section of the General system preferences, you'll see a heading that reads, "Number of recent items" and a set of pop-up menus. This is where you can adjust the number of items for each section of the Recent Items list.