Is it possible to give multiple humanoid models the same animations without starting from scratch each time?
Select the Armature object and Shft D for duplicate.
You can make slight adjustments to this armature to fit a new character in Edit Mode. If the adjustments are not too great, then you can use the same animation very easily. Simply parent the mesh to the Armature and you can have the new character with the same animation.
The animation - stored as an action as well as keyfame data below it - is duplicated with the Armature. You can swap out this action in the action editor also to change to different actions on an Armature. These can also be mixed in the NLA editor. There have been some improvements and changes to this in 2.5.
U can also import just actions from an other .blend, but be sure your armature’s bones has the same name, similar proportions, unobtrusive constraint and limits.