Great discussion on this thread! Though there doesn't look like any 'trick' to keeping the insurance costs down other than the good student / driver's ed / clean record discounts.
Some feedback; my insurance rates haven't increased at all while my son has his learner's permit. Our state law requires that he have the learner's permit at least 6 months and that he completes at least 100 hours of supervised driving (50 hours if you complete driver's ed). This wasn't the rule back in my day and I think the change is good. It allows us to get a good feel for how he's driving before we sign off on the timesheet he needs for his license. The other thing that is heavily stressed with our son is that driving is a PRIVILEGE and not a RIGHT. So if things start to go bad we can take it away (but in reality it might not actually be so easy to do).
Regarding shared responsibility for the cost increase; our agreement is that he will pay half of the insurance rate increase (which I'm hoping is actually feasible with his very limited income). I think this may sway him into getting a part time job which I encourage. On the other hand, he's an excellent student and is taking very difficult classes (AP Chemistry, AP History, and Calculus as a Junior!) - so I hope this whole job / driving thing doesn't change his focus..
I guess one other positive thing that has come out of this driving urge has been that we've spent more time together. As an engineer, I'm a total gear head that loves to DIY for *everything* - especially car related. Usually I'm in tinkering in the garage alone.
However, since he's going to get access to an older 4Runner he's been eager to get it fully up to spec. We've spent three weekends together upgrading the suspension, replacing a failed axle seal, changing the oil, and replacing the rear brakes. It's been a good way to do something together and give him a better appreciation for how a car works.