1) Several phone interviews for an internship. They don't do fly outs for internships, if I remember correctly. I never finished this process because I took another position before the interviews were complete.
2) Phone interviews and fly out for a position about 1 year ago. The team had good things to say about me, but it wasn't a good fit for either myself or that team. I was referred to another part of Apple, where I started over.
3) Phone interviews and fly out for a different position just one week after #2. In a spat of horrible luck, I lost my contact lens at the hotel that morning. I decided that a makeshift eyepatch wouldn't look good, but having only 1 contact lens in gave me a splitting headache. As I struggled more than I should have, I felt them grow more cold. I was kindly told that the interviews were over about 3/4 of the way through.
Similar to jaysonelliot, I didn't sign an NDA and didn't leave the interview room except for lunch.
A few notable things about my interviews:
I was asked to code over the phone. That's much harder than white board coding, in my opinion. It was something fairly easy, though (atoi in c, or something like that).
I felt like I was judged on my Apple culture. When I revealed that I didn't know Objective C, that didn't seem to matter to much, but when I revealed that I didn't own an iPhone or a Mac, I did feel that my answers weren't what they were hoping.
The questions were very broad. Because I come from both a hardware and a software background, I was asked about everything from basic power dissipation to more traditional CS topics.
Honestly, I felt a much more happy and welcome atmosphere at Microsoft, which surprised me. It was kind of the opposite of the consumer perspectives of those companies.