Easy Browsing is one of most important factor of any application populatrization. Browsing is getting easier and easier day by day. First came the horizontal link browsing, then tabs took the place and this is something new, "Collapsible Browsing". Just click and read/collapse. Very much easy to browse google services now. Have a look at this extension of Firefox and if you love gmail, you will love this too.

What is it?
A Firefox Addon that allows you to make the Inbox Collapsible and load your choice of Google Calendar, Reader, Notebook, Groups, Maps, Picasa, Sites, News and Portfolio seamlessly into the gmail interface below the inbox (rather than the sidebar) using a collapsible box. It even supports custom URLs (with navigation buttons) and Google Gadgets (including Remember the Milk.) If your are inbox minimalist, you can even enable minimalist mode to clean up the inbox even more. Works with Google App Accounts and Gmail Themes

Features:

• Collapsible Inbox
• Inbox Box Minimalist Mode
• Embed in Gmail within a Collapsible Box the following Google Features:
  • Calendar
  • Reader
  • Notebook
  • Groups
  • Maps
  • Picasa
  • Sites
  • News
  • Portfolio
  • *** Custom URLs
  • *** Google Gadgets
• Remove Headers in Included Pages
• *** Navigation Buttons In-Frame when Appropriate
• *** 100% from the Ground Up Redesign of the Options Interface
• Works with Google App Accounts
  • Even Allows Combining of Non-App Features with App Accounts

Integrated Gmail is almost ready to use but it is currently an experimental download at the Firefox add-ons site.