5.2. The "Heads-Up" Program Switcher Only one program can be in front, or active, at a time. To make a different program active, you could click or double-click its icon (in the Dock, the Applications folder, or whatever). But the fastest method is to use the -Tab keystroke (Figure 5-3 ). Figure 5-3. Apple calls this row of open program icons a "heads-up display," named after the projected data screens on a Navy jet windshield that lets pilots avoid having to look down at their instruments. You can use this feature in three different ways, which are well worth learning: • If you keep the key pressed, each press of the Tab key highlights the Dock icon of another program, in left-to-right Dock order. Release both keys when you reach the one you want. Mac OS X brings the corresponding program to the front. (To move backward through the open programs, press Shift- -Tab.) • If you leave the key pressed, you can choose a program by clicking its icon with your mouse. • A single press of -Tab takes you to the program you used most recently, and another press returns you to the program you started in. Imagine that, for example, you're doing a lot of switching between two programs—your Web browser and your email program, for example. If you have five other programs open, you don't waste your time -Tabbing your way through all open programs just to "get back" to your Web browser. Tip: Here's a related keystroke, equally awesome. If you press -tilde (the ~ key next to the 1 key), you switch to the next window in the same program.   . highlights the Dock icon of another program, in left-to-right Dock order. Release both keys when you reach the one you want. Mac OS X brings the corresponding program. 5.2. The "Heads-Up" Program Switcher Only one program can be in front, or active, at a time. To make a different program active, you