Gmail Button allows you to add a toolbar button to your Gmail inbox. You can use this in lieu of a sidebar bookmark or toolbar bookmark simply by dragging it to the Menu or Navibar.  

Gmail Button v0.1

P.S. If you open Gmail from a bookmark, you can go straight to New Mail by replacing the target to:

https://mail.google.com/mail/?zx=kksynt1xtviu&shva=1#search/is%3Aunread+in%3Ainbox

Did you know that there is a way to integrate all your favorite sites into Gmail? For example, Facebook, Twitter, Friendfeed, Digg, MySpace, Del.icio.us, and more. Check out this article for adding sidebar widgets to Gmail.

Integrate Facebook, Twitter into Gmail

Straight from the source, advice from Google will help you master Gmail.

Become a Gmail Ninja

I’m sure many of us must have run into this situation once in a while. In a hurry to do something else we must have forgot to sign-out from our email account. Many times we think we need to get back to the same computer to sign-out. Luckily, if you use Gmail then you don’t have to get back to the same computer to sign-out from your Gmail account. Gmail, nicely, allows you to remotely sign-out from all your Gmail sessions. That means, you can sign-out from all your Gmail sessions from any computer that you have access to.

Learn how to sign-out from all your Gmail sessions.