Angie's Oyster Bar & Grill in Singapore implemented a $10 "screaming children surcharge" about a month ago and say that complaints about noisy kids have since dropped. (Earlier this year, they also removed highchairs from the restaurant.) From Yahoo! News:
With the penalty in place, it noted "an improvement and fewer complaints", with customers who are parents being more mindful and making a greater effort to ensure their children are not disturbing others while dining.
Parents and caretakers are informed during the reservations process about the penalty and "99 per cent" of them are very respectful and understanding, the restaurant said.
"We are happy to inform you that the vast majority of our guests understand the policy was introduced with good intentions and appreciate we're doing our best to make the dining experience enjoyable for everyone and not just a select few."