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
geoiplookup.net - (IPv4 only) Online tool to get accurate IP address information
IPTools - The "IP Tools" is powerful and handy application for network analyzing.
whatismyip.cc - External IP Address lookup tool with option to scan the external IP address.