Terrific article on handling "good" advice: Bean Dip! (for AP Parents)

Recently a very good question was asked by Still Kid (see the full discussion here):

I also support this method and find it beneficial. But I meet so much resistance in my family, that sometimes I just feel frustrated if I should continue. Especially, my mother-in-law (as always...) tries to tell me all the stories about her dear son (my husband) who learned how to read only in school, and became of the best readers by the end of the 1st grade. I believe that being smart, he could be one of the best readers by the end of the 1st grade, but he still reads much slower than I do.
You might also meet those “who knows better than you” how to teach your child, but it is so hard to oppose them all the time… Especially when my mother-in-law babysit my child so often! All those remarks: “Oh, he even doesn’t know letters!”, “He doesn’t understand anything yet!”. They drive me nuts…
If you have any suggestions how I can argue with that, I would really appreciate it.
words.

So, how do you handle disapproval of your in-laws or "great" advices of your close ones and just strangers?