This weekend I was a student in a pair of 1-day classes offered by SoloPro Driving School LLC; the "Intro" and the "Comp" classes. These classes teach the fundamentals and some more advanced techniques for autocross driving, built around a formula of one-on-one instruction and lots of seat time, practicing maneuvers and concepts. Each session included two runs through a short course, with an instructor in the passenger seat. Then, two runs as the passenger while the instructor drives my car. Finally, two more runs with me driving, and the instructor as passenger. This worked very well, providing a good mix of instruction in theory ("You want to get closer to that first cone"), with demonstrations of technique ("Do you see how I'm aiming right at that double cone?"), and a final chance to apply this new knowledge almost immediately.
Overall, I was very pleased with the classes. I had to wake up brutally early on both days of the weekend, and spend much of my day standing in a shadeless parking lot, working as a course marshall while other students had their turns, getting sunburnt, but it was great fun and the quality of instruction was top-notch. For less than the price of a new set of tires, I gained a giant amount of skill, without any risk of changing my competition classing.
I didn't have much opportunity to take pictures, but I snapped a few. The set is on my Flickr page.