"Linked" animations

Is there any easy way to align animations for two avatars together so they look like they were built together...I'm talking about things like the Salsa balls...some are really well done, and some need some major help. I'd be interested in making things like this, as I have animation experience, but writing an animation for two different avatars and hoping they link together correctly is beyond my experience.

edit: I'm looking mainly at open-source applications. Avimator doesn't have the ability to animate two figures at once, and then undelete the un-needed ones. Is there another application (besides the expensive Poser) that would help?

Theoretically, all 3D animation programs, such as Maya and Blender can call multiple figures in one scene. But it is impossible that you link them to each other because BVH doesn't allow it. You can use it just a reference and it is not correct at all in world because of the scale issue in world.