In the UK there are groups who get their kids excused from "assembly". I thought that our primary school was good that way, but I did wonder how those excused kids felt being set apart. (Kids always hate being different at that age)
This is something I struggle with. The whole 'assembly' thing, and basically most of the religious content that apparently creeps into even secular state schools. Even though faith is a part of my life, and I plan to teach that to my kids, I just feel really uncomfortable about it being presented to my (hypothetical) kids at school. But, at the same time, I don't want everyone thinking they're freaks or something if they're skipping out on assembly or whatever. Or, at the very least, teachers treating them differently because they have a crazy, difficult, American mother. :p
I know people in other threads have gone back and forth about whether their schools do hymns, prayers, etc, and, like the deal with the Pledge of Allegiance, it sounds like it's very much down to the individual school or district. I suppose I just hope that our local schools won't bother.