stand up, shake hands, and thank them for their time.
if I haven't expressed my personality to them enough for them to have to ask, they are going to be a pain in the ass to work for, and i'm not wasting my time with the rest of the interview.
my last interview, i was introduced to what the comapny was/what they did, and what the position entails. following that were a couple of tech questions about what i would do in X situation. From those, it spawned into more of a casual conversation about 'the life of web developers'. I had an offer within 24 hours and took the job.