Range finder for long ranges

Is there any range finder for arduino that supports long ranges (well, 50 - 100 meters would be good enought). No matters if it's ultrasonic or laser or other type of range finger as long it can measure long ranges. Thanks.

What sort of size of target?
Does it have to be non-contact?
ie, could you use a tape reel?

40ft-100ft, target is a person, yes it must be non-contact, although thought of putting a trigger on the ground.

It would help if you could fill out a bit more of the application.
Like:
What is the environment? Is it cluttered/noisy?
Over what kind of arc is the detection to take place?
Or is the target constrained to a small area?
How fast can the target be moving?
Is the target capable of carrying part of the ranging system?

and so on...