It's interesting that sometimes we enjoy doing solitary things in the company of other people. One example that was new to me is Reading Parties. The Stranger.com reports that The Fireside Room at the Sorrento Hotel in Seatle has such a party once a month and it always packs the room, which looks a lot like an old-fashioned gentlemen's club.
Among the recent reading material was The New York Times, A Brief History of Curating, and Moby Dick.
Apparently speaking in hushed tones is allowed and some couples appeared to be there on a date, while others may have been hoping the evening might lead them to a kindred reading spirit.
Some of the members of my MAD (Massive Action Day) program did something similar online; they declared a reading day and at the start of the day each person shared (in a chat window) the title of what they were reading, and then they checked in with each other every couple of hours to share ideas, reactions, questions, etc. (To find out more about the MAD, go to http://www.MassiveActionDay.com)
Of course writing is also a solitary activity and it's well known that many writers like to write in a coffee shop, library, or other public place. I'm in Los Angeles at the moment, where about 50% of the people you find in any Starbucks are writing a screenplay.
If you're feeling stuck in your writing, try doing it in a public place, it might give you the stimulation or sense of comfort you need. On the other hand if you already do that a lot, try writing in a private space; sometimes it's the change that is stimulating, not the specific type of venue.
(For lots of right-brain tips on writing, get a copy of Your Writing Coach, available from Amazon or your other favorite bookseller.)