Firefox: Integrated Gmail is a clever way to load any Google app on one landing page. With version 2.0, it also adds a lot of interface fixes and helpful features, in the style of a certain well-known Gmail extension.
The basic functionality of Integrated Gmail remains the same — load in other Google Apps, like Reader, Calendar, Chat, Tasks or whatever you'd like, and set how big they are when you click to expand them. New to 2.0 are several features included in Better Gmail 2, like message counts in your web favicon, and a few that are just all-around neat: universal drag-and-drop between left and right sidebars, sidebar and title bar hiding, multiple inbox support, theme detection and compatibility, and much more, detailed at the developer's Mozilla page.
Of course, loading multiple Google apps in a single page can introduce a good bit of lag, and we saw some incessant Gmail load flickering in our installation. With some adjustments though, you can probably create a single-page inbox for all the stuff Google wants to serve you.
Integrated Gmail is a free download, works wherever Firefox does.