Interviewing Skills--The Other Side

I'm on an interview panel at work for an effing THREE DAY INTERVIEW next week, out of the blue.  I have to have a one-on-one session with the candidate for 4 hours one day, take her out to lunch another day, sit through her one hour presentation and another 4 hour panel interview the next.  All for a job similar to mine, which is for the lowest rung on the totem pole position.  I mean, I love my job, but it isn't hard.  It doesn't take a genius to do (obviously), or exceptionally specialized skills, or anything. Nothing that warrants 3 days of torture for someone!  All for a position that is all but filled by one of our freelance, recently graduated students that is 100% perfect for the job and really wants it and it fits in with her career goals.  We are all going to vote for the freelancer to get the job, we love her and she does fantastic work and is great to work with.  It just seems like a huge waste of time for the interviewers as well as the poor interviewee.  I've never done an interview that was more than 4 hours long!

So...any tips on interviewing people?  I have never done so and just plain don't have time to research it, given the insanely quick timing and all of the other deadlines I have going on.  I am glad they are considering my opinion when hiring someone that I will work with closely, but dang if I don't resent the time investment for what I consider a done deal already!  A meet-n-greet over lunch, sure, I can see how that would be beneficial.  But all this time wasted on someone who probably will not get the job?  Nope.