Which Firefox API calls would you use to change homepage in Firefox programmatically?
The purpose is to create a Firefox extension that is able to cycle through a few favourite pages (this is analogical to cycling through a few wallpapers on the desktop).
You can change the Firefox homepage by setting the preference "browser.startup.homepage".
The easiest way to do this in an add-on via JavaScript is:
Components.utils.import("resource://gre/modules/Services.jsm");
Services.prefs.setCharPref("browser.startup.homepage", "http://mike.kaply.com");