Hero Machine Version 2.5 is another Superhero site. This one is very comprehenisive and offers many choices. I particularly like how you can add a companion.
There is also four choices of bodies.
Once you have added all the parts and features to your superhero then you will need to take a screen capture
Update 3 November 2009
Jeff the Designer left a comment about my post and told me that HeroMachine Version 3.0 is in Alpha mode, it looks amazing, heaps more options. Kids are going to have fun with this one!