I know several people who have homeschooled through high school. Many top colleges take homeschooled kids. Of course they still have to do the SAT or similar tests and they have to have taken all the college prep stuff. Most of the kids I know who did homeschool in high school were kids who were very self motivated and did either on-line classes or some other type of distance learning classes. I am homeschooling my fourth grader, but I want her to go to school for jr. and sr. high school. I want her to be able to participate in band and sports and such. I have heard of people getting thier homeschooled kids to participate in certain parts of public school, like music or language or sports, but it takes a fight I am not willing to undergo, since I have three other kids in public school. I also have no confidence that I would be able to give them any help with thier work at that level. LOL
So it is possible, but not something I am willing to do. There are also umbrella schools that you can pay to homeschool under and your kids get a diploma.