Many of the Gmail and Google services have more than once account and sometimes you need to login to multiple Gmail at the same time even though you can only login into only one Gmail or Google Account at the same tome. To solve this issue so you can login into multiple Gmail at the same time there are many ways.
1. Google Account Multi-Login Script
If you are using Greasemonkey script then you will love this script Google Account Multi-Login script., It allows you to login and switch between multiple Gmail and Google accounts using drop down menu at top right. it works with many services of Google service except Google AdSense and AdWords.
Download Script
2. Firefox Plugin Cookie Swap
With this Firefox add-ons you can login into multiple Gmail and Google accounts by using Cookie Swap plugin It allows you to maintain and access multiple profiles at same time and toggle between them anytime
(It works also with any other web service and Email)
Download
3. Use multiple browsers
This may be the simplest way. just download and install multiple browsers to open multi web accounts, For example Open one account in Firefox and another one in Internet Explorer and third in Google Chrome and so on, you got the idea.
4. Gmail Manager
Firefox plugin this is another Firefox add-ons that solves many troubles you can you add all your credentials once and then switch between your accounts as needed, or simply have them all opened it tabs.
5. IE Tab
IE Tab allows you log into two different Gmail accounts at the same time, basically it allows you to open IE inside your Firefox window so you don’t have to have several windows opened.
