Stack Exchange Flair

To replace the signature quotes with your Stack Exchange flair, click the page action icon to the right side of the address bar in Gmail, and replace the array with this:

["<img src=\"http://se-flair.appspot.com/png/921455be-18e4-481e-ba1a-ba1d30998061/\" />"]

Of course, you'll want to replace the image src with your own SE flair! Otherwise, you'll see mine.