EU citizens need a visa to enter Russia.
Until May 14, 2008 visas of other countries (eg. China) entitled to transit through the territory of Russia.
At present, a separate Russian transit visa is required.
In the case of staying in one city longer than for 72 hours, registration is required.
(Citizens of Ukraine can stay on the territory of Russia without visa and registration up to 90 days.)
Standard cost of Russian tourist visa is 137 PLN [2008].
More information:
Information about registration in Russia:
See also: Tourist agencies