[bbx]

Funnily enough, if you Google "Calibri", the page itself is in Calibri. I've never seen that happen for any other font.

[latchup]

It also works for Open Sans, on my Linux system at least. Probably only works for fonts that are installed and/or can be licensed for this.

[sollewitt]

It’s an Easter egg, also for Times New Roman and a few others.

[RobotToaster]

Works for comic sans.

[Ethan_Barry]

Try Garamond!