I saw some guy had a file (I guess a batch file). On clicking of the batch file he was able to log in to multiple sites. (Perhaps it was done using VB.)
I looked for
You can use Autohotkey, download it from: http://ahkscript.org/download/
Autohotkey
After the installation, if you want to open Gmail website when you press Alt+g, you can do something like this:
!g:: Run www.gmail.com return
Further reference: Hotkeys (Mouse, Joystick and Keyboard Shortcuts)