There is one command for this workflow: "ip"
The workflow queries What's My IP Address? to find your external IP, and it uses ifconfig for the rest of the internal IP(s). Selecting one of the IPs will copy it to your clipboard.
Note: After I wrote this, it was pointed out that Ctwise has already written one with very similar functionality, which also let's you get MAC addresses, etc. This one seems to pick up my internal VMWare IPs, but that's about it. Find Ctwise's one here: Network Info.