How is this effect done, the light streaks from the hands... it streaks out from the fingers, then slowly disappear:
YouTube - Anastasia Volochkova - Adiemus (http://www.youtube.com/watch?v=QXUqrFdPlww&feature=related)

looks like a pretty simple particle emitter in Final Cut Studio's "Motion"

That looks like the standard particles you'll find in Trapcode Particular. It's a plugin sold through Red Giant Software. I have a license for After Effects, but I think they also have a version for Final Cut and Avid people as well. To me, it looks like whoever made that animation didn't even change the default colors or particle shapes!

I was going to say After Effects, but after looking at it it looks likes a particle generator from Motion.

Thank you. I don't have a Mac, so I guess Trapcode is my choice. I don't understand how it follows the moving object (hands), so I guess I have to download a trial and see.

Here is an IPod commercial done with Trapcode:
YouTube - #20 - iPod Nano 2G - Colors - The audience is listenin (http://www.youtube.com/watch?v=d4J2Wk9FZdQ&feature=related)