Out of Office Experience

always use this address: https://mail.google.com. It'll make checking your email more secure. Without this extra layer of protection your emails can easily be intercepted and read by wifi snoops.

Lastly, go into your account settings. Under General > Browser Connection click on the "Always use https."

For more info check out Why You Should Turn Gmail’s SSL Feature On Now and Gmail HTTPS Doesn't Protect Account, New Setting Does.

Update
Be sure to check out Wired's Wiki on how to secure Gmail, Yahoo Mail and Hotmail.