'laser' distance measuring devices

heinbloed said:

One thing still: A laser should not be used in public for safety reasons,it can destroy the sight even when the eye is exposed only for a short moment.

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Untrue, lasers come with different classifications indicating their power and ability to inflict biological damage. [broken link removed]
Class I lasers are low powered devices that are considered safe from all potential hazards. Some examples of Class I laser use are: laser printers, CD players, CD ROM devices, geological survey equipment and laboratory analytical equipment. No individual, regardless of exposure conditions to the eyes or skin, would be expected to be injured by a Class I laser. No safety requirements are needed to use Class I laser devices.

As it is a highly collimated beam of light the risk is that it can be focussed by the lens of the eye to a tiny point thus increasing its energy density dramatically - this can damage the retina.

Regardless of laser classification proper safety controls should always be used as good practice.

Thanks zat29! But the question was how to use a laser to measure distances or levels on a distance, read zag's original post again.
I worked with lasers for some time on sites myself but never came across a class I laser. These are simply to inaccurate to give any useable results for a builder/architect/planner ect..see the previous post of Suellen.
But even on pointers of class I the warning is clear:"never look into the laser, never point it on a person or an animal". I used a real "burner" for geological measurings of 50 km distances, no second and one would have been blinded. I still hope I did not do too much demage.