Questions regarding other objects in python

Are there global properties or variables or something? How can I get the properties of another object?

Is it possible to get locations etc. of a different object, or should I try to use some property thing?

Hello

check this, maybe useful:
http://www.blender3d.com/documentation/pydoc_gameengine/PyDoc-Gameengine-2.34/KX_RaySensor.KX_RaySensor-class.html
Bye