I commend you for planning your kid's future. I too started saving small change from whatever a young airman can set aside for their kids. But I changed course after a conference with my two sons teachers.
I know it's not for everyone but something to think about (take it for what it is worth as applicable) ... here it goes.
My wife and I are blessed with two boys that are gifted and loves school. While stationed at Davis-Monthan AFB in AZ, both my boys were enrolled in a Magnate school/Gifted and Talented Education program. Their teachers gave us a different prospective on how to prepare them for college besides investments. They opened our eyes on multitude of programs (scholarships, grants, loans, etc ...) that are available that not many people take advantage of. A lasting word from their teachers stock in my mind to this date - "however, they must make the grade required."
Instead of investing money towards college, my wife and I invested our time and effort, and instilled values on them at an early age the importance of education. I am sure that they remember my wife and I's struggles to get our degrees. It was a lot of work for all of us (our schedule revolved around our kids' school and activities) but it was worth it at the end. We learned that the most critical times start on their freshman year.
Our goal has always been for our children to be better off than us. To make a long story short, our oldest son (22) will be graduating from the US Air Force Academy in May 2007 and our youngest son (19) is a freshman in University of Arizona with full ride Naval ROTC scholarship.
Luckily, it also help that they both want to serve in the military (4th generation). BTW, both my boys were not all straight A but were honor students and scored high on SAT/ACT and other measured factors as a whole.
Again, thank God this worked for us, but please understand this is not for everybody but something to think about and consider.
Sorry for the long response. Good luck!
V/R
Ed