lissener nailed it. I had the same experience. Finding a school that is willing to treat your child as an individual and provide them with the stimulation they need is nigh impossible. Most likely, they will be bored out of their minds every single day they spend in school. I was.
The only concession most are willing to make is to allow a grade skip. Okay if you skip second grade, but not really okay if they want to put a six year old in sixth grade. I was home schooled from the fifth grade on, and started college two years later.
There is no reason to hold your children back; if they seem eager and interested to read and write, teach them. But monitor their school situation. Don’t be afraid to try to get them what they need to stay motivated and challeneged. If you do have problems on that front, there are always magnet schools, private schools, montessori schools and home schooling.
No matter what you have to do, the important thing is that they always stay motivated to learn.