I enjoy both Myspace and WoW...but I wouldn't let my 9 year old daughter do either. Once she is older, I may allow her to have a Myspace, but under certain conditions, like she can only add friends and family, her profile must be private, she can't give out any personal info, and such stuff like that.

As long as you monitor your child's activity online, and talk to them about why some things need to be personal, then it will be easier to avoid the online horrors.