On-screen RulerScreenshot 


This program is a semi-transparent on-screen ruler with keyboard shortcuts to help you lay out GUIs and Web pages or measure anything on your screen in 5 units. Right-click to learn the options and shortcuts. The ruler saves its settings upon exit, so it always looks the way you configured it last. The program comes with a built in uninstaller. It is safe for work, since it does not modify your registry.

Screenshot of On-screen Ruler