IP Broadcaster is a customizable menu display for live WAN and LAN IP numbers. One of the available numbers can be displayed in the menu - which one is displayed is determined by the user. A default for display can also be specified in the program's preferences. There is a manual refresh command in addition to automatic checks every 30, 60, 120, or 300 seconds, and the addresses may be copied to the clipboard instantly by clicking on them.
While a little investigation makes it obvious that the commercial intent of this application is to generate publicity for the developer's other applications, that factor does not detract significantly from IP Broadcaster's features other than through the presence of an inconspicuous ad for "Other Network Tools". It does what it says it will, with enough technical precision that Mac geeks should find it a boon.
Sam's Protip: If your menu bar is running out of space for background apps (as mine is - oops), it's probably best to use the icon for IP Broadcaster instead of the text. Better to have the application accessible with a click than completely invisible!