Create A Special Permission in Firewall.......

How would you set up a special permission in firewall to block a computer from being Pinged.

Class project that I cant figure out.

By default, incoming echo requests are allowed and other ICMP requests are disallowed. See the following article on how to change it.
Vista Advanced Firewall config features

You'd need to enable the outbound firewall, since a ping reply is an outbound message.

block all outbound connections under the profile you connect with (Domain/Private/Public), then create outbound allow rules for ie, and other programs that need internet access under that profile(s).

Note- I personally would set up the Public profile as the block all, and only create IE rules. There will be no pop up warnings for programs not allowed internet access (including windows programs), Each rule for each allowed program will have to be created individually. For Private (home) profiles It is easier to Use a router for two reasons:
1. Hardware firewall
2. "Block anonymous Internet request" can be enabled/disabled