One category which I definitely think should be billable is the interview when there is no actual job or no job as advertised. There were a bunch of stories go

One category which I definitely think should be billable is the interview when there is no actual job or no job as advertised. There were a bunch of stories going around about some insurance company calling people in to interview for database jobs and then trying to sell them on insurance cold-call sales positions. Another one is those interviews at large companies where they must conduct x number of interviews, but they already have the person they want and they're just going through the motions. This would be difficult to prove, but I've heard managers directly say they are doing this.