topic says it.
Rules:
--There's basically no true isolation in the world, so it doesn't have to be perfect (Example: solitary confinement at a prison counts, even though somebody brings you food)
--Posting on forums counts as social interaction
--having a boring social life where you stay at home and don't do anything but text with people, facebook, and gchat isn't really isolation
For me, I think it was the "solo" portions of some backpacking trips I did with my high school. We were given a small area of land in the middle of the forest that we could move around in and explore, but we weren't supposed to talk or try to find any of the other people on the trip. We could talk with the trip leaders, who would visit once a day. They dropped us off, then visited us 24 hours later after the first night-- so I think the longest I went was that one day! But after the trip leader visited with me, I snuck off the site, found my friends and we hung out and smoked weed the rest of the night, then it was over the next day.