Many actors are confused about whether or not they should memorize their lines for their TV and Film auditions. One camp says to always be "off book" and another says to barely look at the material so that it stays "fresh". I believe that each audition is different. Sometimes I memorize the text completely, sometimes just sections. Sometimes at a reading I am asked to stay and read for another role so if I am married to the idea of always memorizing I am in big trouble.
I have had a lot of writers, producers, directors and casting people come out and speak to my class about auditioning and they all agree that they don't care at all if an actor has the lines memorized. In fact the writers, who are usually the executive producers on the shows we audition for, always prefer that actors use the script--they want to hear their lines read correctly! What all care deeply about is that the actor bring life to the role. The actor should be as memorized as necessary to accomplish this.
Here is a video I found on YouTube of Hugh Laurie auditioning for House MD. I think it is a great example of an actor using the script while still bringing a full realization of the character.
Click here to see the video.
Note when Mr. Laurie apologizes for his appearance at the beginning of the clip, saying that "things haven't been going well lately". I may be completely wrong here, but I suspect his choice of appearance was quite deliberate. Perfect for the role.