Hi, 10Smiles - I'm Kate, Steve's other half.
Do you use a curriculum - i.e. textbooks? We unschool, but I'm still concerned about the weight of our "school stuff" (mostly paper weight) when we travel this summer, so I'm always curious about how other people/Airstreamers deal with that issue. Steve's been researching different activities and field trips along the route we're taking this summer, so we're super-excited about that. I see a lot of hands-on learning in our futures!
Perry, you can talk to your local school district about homeschooling. Some are very accommodating - for instance, when my parents pulled me out of school the first time, I was midway through fourth grade. Our school district allowed my brother and me to finish the year at home, and basically told my mom what we needed to cover to advance to the next grade level. That said, some are decidedly homeschool-unfriendly, so you might want to do some research before you start asking "official" questions.
And 10Smiles, I totally agree with you that homeschooling seems to work - after being homeschooled on and off through grade school and unschooled all through high school, I went to college and graduated with a degree in psychology (which helps me homeschool our two little ones, lol.)