How do I find out what my external IP address is?

Question

My computers are sitting behind a router/firewall. How do I programmatically find out what my external IP address is. I can use http://www.whatsmyip.org/ for ad-hoc queries,

Answer 1

curl ifconfig.me

or

curl ifconfig.me/ip

Incase you don't have curl installed,

wget ifconfig.me/ip 2>/dev/null && cat ip

Hope this helps.