Screen Loupe 2000
Screen Loupe 2000 is a small utility that displays a magnified view of whatever is beneath the mouse cursor, much like a jeweler's or printer's loupe. You can copy the contents of the Loupe window to the clipboard as well. The captured image can be pasted into any graphics program and most word processors.
Screen Loupe's main viewing window can be resized, and an option is included to lock the current view. This makes Screen Loupe a great screen capture utility. The current desktop coordinates of the mouse cursor and the RGB color of the pixel directly underneath the mouse can also be displayed.
More information: http://www.gregorybraun.com/Loupe.html