I went through 3 phone interviews before being asked to come in for a in person 3 hour interview for which I had to take a vacation time from my current job to attend.
At the in person interview I was taken to several different areas to interview with several different groups of people who all basiclly asked the same questions as the previous group. This continued on for 3 hours.
I thought the interview went very well but I never heard back from them even after a follow up email. Pretty unprofessional considering I took a vacation day to go there and spend 3 hours of my time with them.