Actually, the TCP/UDP *echo* service uses port 7, not the "ping" service. The echo service is something that runs on a computer and is designed to echo back any data sent to it. This doesn't run on all computers, and is a completely different concept than ping (which is what Scott was trying to say).
ICMP is a packet control layer and doesn't use ports at all. The concept of a port does not apply to the ICMP protocol. "Ping" uses ICMP to do its thing, and the Windows TRACERT (and PingPlotter in ICMP mode) does as well. All traceroutes use ICMP to receive data back about the route.