1)   Pixel Ruler 3.10
Pixel Ruler features horizontal and vertical orientation, dynamic mouse measurement tracking in pixels, cool design.

 2)   Webmaster's Toolkit 1.71
Webmaster's Toolkit - utility that allows you quickly measure the size of objects on the screen with pixel ruler, picking the color value from any pixel of the screen and alter or produce your own colors with the Photoshop-style Color Picker.

 3)   MioToolbox 2.12
Five handy graphics tools available at any time from a single mouse click: The pixel ruler, color picker, screen capture, lens, mouse lens, and more.