Have you had the "talk" with your children in regard to strangers and getting rides, looking for "lost" puppies, etc.? I highly encourage you to do so. There are many child abductions per year, and sometimes it is someone that is a family friend! I hope that you have... if not, please do it today or tonight. Remember to give them scenarios... and what to do. Also, follow up with them... make sure that they totally understand!
One area that my neices and nephews and I are very open about is not touching ones private parts, too. THIS IS CRUCIAL! Most child molesters are family or friends... that means someone that you know and trust! Remember to tell them that nobody is to ever touch they're privates for any reason unless they're hurt, they go to the doctor, etc. And if it does happen, they should tell they're parents right away!
I just think about these people who do these things to kids and it makes me sick! Parents, please be on guard.. talk about it openly and often. I have discussed this openly with my sister and parents right in the room with them. Also, how there is no such thing as "secrets". Most importantly, there is no such thing as "accidents", either!
When your child is old enough to wash him/herself, you should talk to them about this. Even if they do not fully understand, keep going at it. Sexual abuse scarrs for life, as so many of you people know. It can ruin entire lives, and it is important that every one of your kids knows the boundaries well, and what to do if something goes wrong.