Remember, in August, 2010 Google came up with new features to "Access two Gmail accounts at once in the same browser" which increased to three Gmail accounts after few days.
What is the new thing..!!
New thing is now you can access more than 3 Gmail account at once in the same browser.
How I found it...!!
Actually, half an hour back, i was using my three Gmail account in Google’s Chrome and fourth Gmail account in Microsoft’s Internet Explorer (Explorer). As usual explorer was very slow and i was unable to send a single email from my fourth Gmail account opened in Explore.
In frustration (just to try), I tried to access my fourth Gmail account in chrome, remember I have already opened my three Gmail account in same browser (Chrome). I knew that i would not able open my fourth Gmail account in Chrome but i just tried. Otherwise, I have to logout to Gmail account and then login to fourth account.
I knew that it would not going to happen but i just tried and surprised when Gmail has not denied to giving me access of my fourth Gmail account in same browser (Chrome). Great....
So, why to wait now enjoy more than three Gmail account in the same browser...
Have a look of picture (click on the picture for large view) given below, in which i am accessing my fourth Gmail account.