I did this in January 2013.
I got my visa through gotorussia.com and it was a simple process. I will use them again when I go back.
I gave them a window of when I would travel and a nonrev listing.
Russia generally gives 30 day visas so if you don't go in that 30 day window, you have to get a new one.
My friend who was to go with me, used travisa.com and they gave him a 3 day visa for his exacts dates only. We did not go then because of full flights so he got screwed and had to buy a new visa.
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