To perform multiple login ID's on forum, facebook, web e-mail accounts (like Gmail and Yahoo! mail) as different users at the same time, try CookieSwap. CookieSwap will swap all your cookies and change your browser at the same time so that you can logged in as a different user id

Download CookieSwap here

Install (Add to Firefox) and restart Firefox

Login to use Profile1




The first cookie is saved





Change Profile1 CookieSwap to Profile2








Profile2 mode




Logout Profile1










Login to use Profile2 cookie



Cookie is save on Profile2



Profile2