Please consider changing the default for auto-refresh in Magnifier so that it is turned on on install. I am assuming it was defaulted to "off" for efficiency, but please consider my experience: I have been using Magnifier in tandem with Mioplanet's Pixel Ruler for the purpose of counting pixels on a web page I am developing. After spending an entire day trying to figure out why my pixel counts weren't achieving the expected results, I finally discovered that Magnifier was not reflecting the image accurately. It was not updating the magnified display after finite placement of the ruler and since I was looking at the ruler in the magnification window, my counts were off by 1 pixel. Over an entire page of measurements, those 1 pixels add up. I finally discovered the auto-refresh option, which solved the problem.

Each person who uses Magnifier will likely respond differently when asked whether they place more importance on efficiency or accuracy. Considering that the auto-refresh checkbox exists to make that choice, and that the perception new users will have is to expect that the magnifier exactly represents an area being pointed to, I believe that it is critical that Magnifier install with auto-refresh turned on.

You're right that we have the option checked to save on efficiency, but it is also useful in situations where you want to save an area without moving the mouse. I do see your point and we'll change the default in the next version.

As far as on-screen measurement, screen rulers are often unreliable as you can never be sure which pixel they are counting from. That's why we have the Screen Calipers:

http://www.iconico.com/caliper

The caliper are nice! and are definitely inticing. I'm sure they are better than what I am using. I'm paying insurance on 3 kids of driving age and 2 that are in college. I gotta save everywhere I can!