How create Action strip for more objects in NLA how can I do one clip for many animated objects? I can add objects to Keying sets and key together, but clips are created separately for every object, but I want create only one clip. Thanks 

EDIT
For example: I will create robot with custom rig. Two legs, one body, two hands. I dont want use armature. And if I will make walkcycle I will have many clips for one walkcycle? It has not sense for reusing, because I will have many clips for one walkcycle. I can use Armature, but often it is not character animation. Last project what I done was house which was rotated, open roof and open windows. This action was repeated. So in Softimage I made clip and used it again. Without armatures or any bones. Maybe it is not possible in Blender.
You only need to animate one object, then copy it to the others. To copy, select all object you want to use the same animation data, the one to copy from as the last selected. Then execute Object > Make Links... (shortcut Ctrl-L), and choose Animation Data.



Note that if Location property is keyframed in the action, all objects using the action will jump to the same location. To offset from original location, use Delta Location instead. The same goes with Rotation and Scale properties.

EDIT: If you want to merge animation data of several objects, I don't think that's possible. At most, you can manipulate all of them in the Dope Sheet, where animation data for all animated objects are displayed. I use this a lot when I have to synchronize the animation of several objects (three, in illustration below) at once: