Interesting question. And everyone is different, so it depends entirely on you. Personally, I tried to show another side of my personality. I talked about how much I loved Japanese food. They spent another 5 minutes talking with me about different Japanese food!!!! Really took the edge off the interview (too bad we did it at the end XD)
Anything that engages the interviewer? I know at one point (clearly had some rapport, already, I thanked the interviewer, and wished them a good day, and asked them something vague, like, if they were nearly done for the day or were there for the next session, which led to a chat about their experience of the interviewing process. We both kept it highly professional, obv. At anouther station, an interviewer had been especially interested in one particular job I'd talked about, .so I asked her about that, if it was a feild she was interested in, etc. Small talk, basically, because it was relevant. You could ask - maybe - one opinion question. Eg. I'm really interested in your rural placement program,. Even though i'm not sure what i want to specialised in....do you think the program effects students perceptions..... If you wanted. I must reiterate, though, the importance of not.asking anything you could Google, and focus on smiling, shaking hands, and taking them, sincery, for their time.
[MENTION=998]Season[/MENTION] : only just seen this, it's terrific.
@ all: seasons advice in the iqt threads made a huge and maybe crucial difference to my interview performance, I Think. I'd suggest you guys use them.