The author's cameo...

[Ayriana22]

<gets out her sack o' hammers and brass knuckles>  C'mon ladies!!!

[Fuzzy Necromancer]

There are two things when I consider a good cameo:
1) It is way in background and not too distracting, flowing with other actions/scenes in the movie, or
2) The person doing the cameo is at least doing something, either advancing the plot, or making creating a light, comical moment.

Meyers cameo in Twilight had one specific shot concentrating on her for no damn reason, then cutting back to the characters in the movie, which Hitchcock avoided in his later films because they were too distracting.

On the plus side, it wasn't taking away from much. The order served up for Meyers probably saved us from another 5 second silent staring scene.