IP Guide - Look up IP addresses, networks, and ASNs
whatismyip.cc - External IP Address lookup tool with option to scan the external IP address.
GRC Port Scan - GRC Internet Security Port Scanner. Tests for open ports on your external IP address.
What is My IP Address - Open Source Website To Get Your IPs Address By WebRTC
IP-Toolbox.com - IP-Toolbox.com is the best site for quick and easy viewing of your public IP address and other related information.
ShowIP - ShowIP displays the IP address(es) of the current page in the status bar.