How to Use a Custom Background in Gmail

If you spend as much time with a Gmail window open as I do (thanks, Multiple Inbox feature!), you’re probably over the rather dull default theme. And even if you’re using one of the many custom themes available, maybe you’d prefer something else. Good news, everyone! You can use a photo from the web or your own computer as the background image, just like on your computer desktop.

via: howtogeek.com