1)   AltSwitch 1.1
AltSwitch is an advanced replacement for the standard Windows Alt-Tab task switcher. AltSwitch lets easily navigate between tasks running on your computer. For each task small preview image is displayed. Skins are supported.

 2)   WinGlance 1.2.8
WinGlance is a visualizable ALT-TAB replacement task switching utility. It lets XP users switch from one open window to another, with only a click at the full-screen neatly-arranged window-snapshot list activated by Alt-Tab or mouse gesture.