Dialogue with people talking on the phone

Get another answer, but I think you can introduce the scene as a phone conversation. After that, write the scene without slug lines for each character change. And once its over, you will have another slug line that will give different info.aka the next scene.

I think its ok to introduce each portion of the scene, then use intercut such as:

INT. CAR - DAY

Dave is driving along the freeway with his cell phone against his ear.

DAVE
Yo, Brandon! Brandon, can you hear me?

INT. BRANDON'S HOUSE - DAY

Brandon walks around on his cell, trying to get dressed.

BRANDON
Dave? Dave, you're breaking up. I can barely hear you.

INTERCUT - CAR/BRANDON'S HOUSE - DAY

DAVE
Dialougue

BRANDON
Dialogue

DAVE
Dialougue

BRANDON
Dialogue

END INTERCUT

...

Though I might be wrong on the exact format of this, but I think this is correct.

Awesome! Thanks!