Change Gmail's Default Text Style

If you like to use rich formatting when you compose Gmail's messages, but the default text style is too boring, you can change it. Go to Gmail Labs, enable "Default Text Styling" and change the style from the settings page. You can select a different font face (including Comic Sans), change the color, size and style.

"If you live and breathe code, now you can set your default text style to a monospace font. If your life is purple, your email can be, too. But remember: whatever you see is what your recipients will see, so be nice to them and try not to clog the intertubes with ginormous bold italicized red script," suggests Google.

The new text styling is only used when you type some text, so the signature will use Gmail's original settings.