I'm on vacation from the high school I teach at (1st period, 5 days a week).
Unschooling is very different than that model. It's predicated on the premise that humans enjoy learning and that they will be driven to seek knowledge and that what children pursue will lead to acquisition of knowledge in the most effortless and pleasant way.
During "vacation," Chana (7th grade) finished Parshas Shmini. She's reviewing now. We didn't do very many rashis in this parsha and I don't think she knows them very well, but perhaps she now knows what אע"פ stands for and that is great. She is also continuing along the algebra program of mathtv.com. Jack (age 4) has been counting things all over the place. He's counting and subtracting and counting in different groups to make sure they all add up the same. I assume this will eventually lead to a certain math intuition. It's kind of funny that at some point in life, a small child isn't really sure his hand always has 5 fingers.
Yesterday, when I was up to my elbows in pizza dough, with Jack helping me, Sarah (college) started playing with Jack and he started talking about his bones by his mouth. I asked her to show him some pictures of skulls and jaw bones, and Sarah pulled her ipod out of her pocket and Jack was fascinated to see what the bones looked like under the skin. He noticed there were sockets for eyes and nose, and Sarah explained that those weren't made of bone and she told him about cartilage and they squeezed their ears and noses. (Just how unbelievably cool is it that children have access to science images of whatever they want whenever they want?! In their pockets!! What a world we live in!)
Jack is also (and Aharon, age 2) asking me to run through the aleph beis flashcards nearly every day. He's learning a few of them, too. Personally, I don't care whether he learns them or not, at this age. He also keeps looking over my shoulder when I'm reading and pointing out different letters. Also, during commercials, he keeps seeing letters that he knows and shouting them out. I'm not teaching him anything (though of course, when he asks me which letter that is, I answer). Even before I unschooled, I always considered 4 an age where I don't really have to actively teach anything, and I find a lot of kids learn the letters somehow and get a rudimentary grasp of biology and body systems.
Elazar (grade 1) woke me up this morning at 8am (I'm grateful he held himself off for so long) because he needed help writing. He has a piece of paper with a few words that he writes frequently, but he needed some more words. He's discovered that when he creates games, he can make a text box pop up and taunt the player (Hahaha! Bowser will get you!). Also, he needed some help for some of his google searches.
So "vacation" doesn't really end up being different from any other day.