You've been waiting for a chance to use that, haven't you?

"I was waiting for the perfect moment to use it."

There were a few key points where I was waiting for him to use the word.

Two people were ahead of her waiting to use the new system.

"How long have you been waiting to use that line?"

Somebody standing next to me, waiting to use the phone?

He'd been waiting for a long time to use it.

I've got somebody standing here waiting to use the phone.

She says some of her friends "would rather wait to use facebook.com until they get to college."

Been waiting for a chance to use one on something.