The Bible talks about rebellion being like witchcraft. This can be as simple as co-existing the Law as rebellion against God and in its essence being mesmerized by your own self-seeking power. The point I'm trying to make is that people celebrating Halloween isn't the issue. Easter is a Pagan tradition, celebrating new life within the chaotic and volatile state of nature— someone practicing witchcraft in effect is no different to someone following the Law of Moses (Galatians 3:1), so we all have this bit of heresy within us which tends to be purged out by the revelation that we are the righteousness of God in Jesus Christ. (2 Corinthians 5:21).
I say this because I don't think this really deserves its own thread.
Christianity tends to have religious values in opposition to magic and anything that celebrates witchcraft. The world doesn't follow this system— some people want to do Halloween, other's don't. Making people stop Halloween doesn't bring them to the recognition that they are the righteousness of God... and to be completely honest with you getting people to pray on Christian Chat dot com isn't going to cause the entire festival to dissipate into nothing. I know you don't like Halloween, so don't do Halloween.
You could put the same argument forth about Superman— kids everywhere are "mimicing this godlike saviour who can fly and defy laws on the earth that God has set in place" but nobody bats an eyelid. But the moment a child starts pretending he's Harry Potter all the Christians flock to it and begin to trash about making mammal-like noises. Even as I said before, Easter is a pagan tradition, it's just that Christian's adopted it to advance Christ but because society doesn't portray it by it's origins people like you don't seem to care about it but will not be happy at all with something like Halloween because of its modern standard.
If you really want to make a difference, I suggest you hand out flyers with your "treats" and tell kids about how much Jesus loves them, and how He wants to live inside them, and how they're so precious to him. Go out and love on some people dressing up, tell them that they're beautiful and God thinks they're amazing. Don't try to get them to stop doing what they enjoy, because it's not even necessarily an evil root that needs to be addressed— but He has handed us the message of reconciliation, that He is not counting the world's messed up state against them but sent his Son to die as an expression of His love. That's where your concerns should be; not with our opinions, agreements and prayers towards the state of a world that is hostile to God's very nature anyway.