Here is a quick macro video of Pandora doing one of her meow-yawns, a meow that gets interrupted by a sleepy yawn: (Update: As Flickr video embeds no longer work, you will have to click the thumbnail below to see the video.)

Pandora Meow-Yawns (cat video)

When I play back this video on the computer she perks up at the sound of the meow and looks around for the other cat who sounds just like her.