In theory, you can manage out some kind of document from notaries says that your friend delegating you the right to provide the documents for visa application, but it still has to be an original of his passport in your hands, as the visa is being posted in the passport:
- A valid original passport, which has no less than 2 blank visa pages. The passport must be valid for 6 months after the date of visa expiration;
Prices for 30 day visa with a tourism purpose is
35 + 21 EUR, and it will be done in 10 calendar days (so, it's about 2 business weeks). In case you need it in a hurry, you may apply for urgent 30 day visa with a tourism purpose, but this will cost you a
70 + 21 EUR, and it will be done in 3 days (visa is valid starting from the 4th day).
What you can do for save your time is to arrange the appointment in Russian Embassy
Note that there is an exception from visa for cruise ship passengers, who spend less than 72 hours in Russia, but in this case you will be limited in places you can go in participating cities (for Baltic sea they are Kaliningrad and Saint-Petersburg).
I found some other site for getting the visa for 4 days with touristic purposes, but it seems like a travel agency, as their prices are a bit bigger than official ones (link in Russian).