I received an e-mail less than a week after applying for the position on the website. The initial phone interview was less than a half hour and consisted mostly of simple background questions about SAT/ACT scores and questions about the position. I was told that the screening was mostly just to see how well we could communicate.
After that screening, I was contacted about taking a skills assessment test that had a math, verbal and programming section. The questions weren't too difficult and the programming section was supposed to see how well you could learn new topics quickly. After taking that test, I received another e-mail about visiting the campus in Wisconsin. It seemed odd to me that they flew so many candidates after so little screening.
There were probably 30 people there interviewing on the same day as me. The campus and cafeteria were nice, but the whole "unique" experience was a little overwhelming to me. We spoke with a variety of different people in the position that we were applying for. I had to make a short presentation to a group of three people. I had one interview where I read a case study and then discussed it with one of the consultants. At the end of the day, I had another interview with an HR lady.
Had I received an offer, I would have accepted because of the current job market. If there were a variety of options, I would probably pass because of the amount of travel involved.