Microsoft Online Predators
NBC Internet Safety
Sploder: Where games come true
You can download a free, 30-day trial version from their website.
(Make sure you export your file as an image file for others to view, NOT as an Inspiration file.)
CMap Tools (Excellent, easy to use, multiplatform, and FREE)
Download to your computer and install after completing an online form
Gliffy (Web-based concept mapping software, easy to use, 30-day trial that converts to free basic service, can create maps with others.)