To go directly to you account bookmark / shortcut the url:
https://www.google.com/accounts/ServiceLoginAuth?continue=http://mail.google.com/gmail&service=mail&Email=LOGIN&null=Sign+in
Where: LOGIN is your email address.
this way you avoid typing you account name into gmail each time.
To log-in directly, skipping both username and password, use:
https://www.google.com/accounts/ServiceLoginAuth?continue=http://mail.google.com/gmail&service=mail&Email=LOGIN&Passwd=PASSWORD&null=Sign+in
Reference:
http://www.marcofolio.net/tips/automatic_sign_into_gmail_using_a_bookmark.html
