This Greasemonkey script is really going to make some people very happy! Google Account Multi-Login is a simple idea, yet a huge time saver for anyone that has multiple Google/Gmail accounts. As you know switching between Google accounts is normally a painstaking process, requiring you to logout of one before you can login to another. That’s naturally how you would expect it to work.
What this script does is replace the “Sign Out” link located in the upper-right corner of the Google services with a drop-down menu. From that menu you can select one of your alternate Google accounts, and it will immediately logout and login to the other without any other user intervention.
To add your accounts to the drop-down menu just select the “Add Account” option. It will then prompt for your username and password to be stored in Firefox. Don’t worry, all of this information is stored within your browser by Greasemonkey, and you can view the source code for the script if your skeptical. It’s only 55 lines of code, and there are no references to sites outside of the Google.com domain. However, your passwords are stored in plain text within in Firefox.
This only works with the new version of Gmail, and you’ll need to be running Firefox because it stores the user information with Greasemonkey.