What is my IP? - Find out what your IP is. Do not hesitate to open wimip.
ipinfo.io - Simple IP address information.
GRC Port Scan - GRC Internet Security Port Scanner. Tests for open ports on your external IP address.
FindSiteIP.com - Website IP Address & Host Name Locator
My Public IP - My Public IP is a utility to let you know through which internet IP the world see you.
IPTools - The "IP Tools" is powerful and handy application for network analyzing.