Knock knock. Who's there? Lettuce.

Lettuce who? Lettuce in, and we'll 'romaine' here all night, serving up 'head'-spinning puns until you 'leaf' feeling 'crisp' with laughter!

Knock knock. Who's there? Byte.

Byte who? I'm having a little trouble processing your question.

Knock knock. Who's there? Next question.

Next question who? Next question... oh, this isn't an interview!

Knock knock. Who's there? The door.

The door who? The door you just knocked on. It's not a person, it doesn't have a name.