From LifeHacker.com:
The Twitter gadget is made for Gmail and goes "fullscreen". The same goes for Facebook, although it's originally made for iGoogle, you just have to click on "Expand" inside the gadget box.
To install them, do the following:
1. Go to Settings –> Labs, find "Add any gadget by URL" and activate it.
2. Find a XML gadget for Gmail or iGoogle.
3. Go to Settings –> Gadgets, enter the gadget URL into the text box and click Add.
These are the gadget URLs:These are the gadget URLs:
For Twitter: http://twittergadget.appspot.com/gadget-gmail.xml
For Facebook: http://hosting.gmodules.com/ig/gadgets/file/104971404861070329537/facebook.xml
References:
From the Tips Box: iPhone Stylus, Touchpad Middle-Click, and Focused Browsing. LifeHacker, 2009. LifeHacker, 2009.