Has anyone done this new 72 hour visa-free visit on the St. Peter Line ferry from Helsinki? I wanted to know what the trip over was like and how easy the arrival/departure were? Can you stay in any hotel in St. Petersburg? Does anyone know of any affordable, non-smoking accommodations there?
Your best bet is to research the Department of State website and/or contact the consul directly. I was in St. Petersburg this summer with a tour for the day. Since I was with the licensed, organized tour, I could utilize the 'visa-free' time period. As far as I'm aware, you still need to be with your guide at all times though. Coming into St. Petersburg at the piers is easy if you have the proper paperwork.
According to St. Peter Line website you are only required to purchase a shuttle bus transfer from the ferry company for getting from and back to the ship and to have a written confirmation of a prepaid hotel for your stay. It just wasn't clear if there were "official" hotels or not.
We arrived by cruise ship with a pre-booked tour and slept on the ship. If you're sleeping on land, I suspect your tour will make sleeping arrangements as part of the tour. If not, Russian immigration will want your "invitation" (information about where you will be staying). The tour (Alla tours) told me exactly what documents to bring when we went through Russian immigration. We had the exact documents and had no problem getting in without a visa. The people at immigration are a surly bunch and not likely to give you a break, so make sure you have exactly what your tour tells you to bring. On the first day, immigration gave us a little red slip of paper. I had heard you need to keep it, so we tucked them into our passports and into our moneybelts. I think immigration only uses them as a reason to levy an instant fine (for not having them). They didn't seem to care much about them when we went back to the ship.
I tried to look up information about this visa-free option you mentioned, but got no clear information. I would try to contact the St. Peter Line directly for specific guidance. In 2007 my friend and I has to pay $100 dollars each and get visas just so we could spend a night away from our cruise ship and move around on our own for a few hours. If there's been a change, that would be great.
Link for visa-free ferry info is: http://www.stpeterline.com/en/Goodtoknow/Visafreerule.aspx. You can also click in upper left hand column for a more detailed manual, but that does not specifically mention if there are certain hotels at which you need to stay.