Not sure if you guys are making it this far inland, but Moscow is cool. Gotta go see the Kremlin and St. Basil's, of course. No shopping trip would be complete without visiting Gum (off of Red Square). Go see anything playing at the Bolshoi ... it's worth the price of admission just to gawk at the furnishings. More museums to shake a stick at, lots of mafia violence and a generally beautiful (kraznie - the Russian word for "beautiful" and "red") city.
Metro system is easy to figure out even without knowing the language and when I was there it was only 10 rubles to get on ... now it's the most expensive city in the world, so this has probably changed.