I am sorry I cannot answer your question because I forgot to take anything with us on the trip and I didn't notice if anyone else did either. Perhaps you could take something anyway; it would be a nice gesture.
I would like to say that you are in for a wonderful trip; we went last summer and enjoyed it immensely. We especially like all the things you could sign up for in Moscow; The Russian Circus, Swan Lake Ballet, a Folk Dancing show. The only thing we did not think worthwhile was the one where you meet the Russian Cosmonaut (don't remember what that was called).
Have a great time.
We liked it so much we are hoping that Grand Circle will have a trip like Viking offers called "Footsteps of the Cossacks" whic covers Odessa to Kiev. However, we prefer waiting for Grand Circle to offer it (maybe 2011, we hope).
You are in for a real treat!