We are planning two weeks to see St. Petersburb, Tallin and Stockholm. Does it matter whether we start in St. Petersburg or Stockholm? Are there problems getting in and out of Russia? Thanks!
The big problem is that you need a visa and hotel invitation to get into Russia. If you don't already have one it's best to use visa company that handles everything for you like this: http://www.gotorussia.net/ These companies have a arrangement with hotel in St. Pete for the invitation. You're under no obligation to stay in the hotel the invite originates from.
You can stay in St. Petersburg up to 72 hours without a visa under their visa-free rule if you arrive by ferry or cruise ship. If this is sufficient time for you, see the ferry line website, www.stpeterline.com, for detailed info. Or PM me for details about our trip last June from Helsinki to St. Pete on an overnight ferry, two nights in a hotel, and return on the overnight ferry. To answer your question, you might consider starting in Stockholm, ferry to Helsinki, ferry to St. Pete, ferry to Tallin via Helsinki, and fly home from Tallinn. All the ferries are overnight except from Helsinki to Tallinn. Have a great trip.