Re: Registering Visa help
Well, I just got back from visiting friends in Russia, but they were Russian citizens. The owner of the apartment was my friends dad, and he wasn't the landlord...he was the owner of only his apartment. He had to be present at the OVIR office with his domestic passport and, I think, the papers that showed that he owned the apartment. When I was registered, they looked at my passport and registered me.
Officially, you must have your passport and visa registered within three days. My friend told me that even Russian citizens have to do this when they go to another city and will stay for more than three days. I would think that the OVIR office would understand...but then again, it isn't America and they usually want large sums of money to facilitate "understanding." If I were in your place, here is what I would do... a) Look for a nearby Russian friend to help, b) Ask your friend if she has any Russian friends who would be willing to register you in their apartment, c) Go to a hotel and ask the front desk to register you for the duration of your stay.
I've heard that it is possible to register your visa at hotels without renting a room, just slip the person a $20 in US currency and they will help you. I never did this because I didn't have to, but money is the key to making just about anything in Russia easier. I really don't think they would only register you for one day...that would be a lot of paperwork over one month!
I would really recommend trying to find a Russian "friend of a friend" to register you in their apartment. It's probably the easiest way, usually people look at the address registration, they don't drop by for a visit as far as I am aware. By the way, what type of visa do you have and who invited you?
Anyway, I hope that might have helped a little since I see no one has replied to you in over a month.