I applied through a recruiter. The process took 3 days. I interviewed at Google in May 2010
Interview
Got contacted by recruiter, had to choose which location and position, I wasn't actually looking for any particular position, so software engineering it is. Phone interview was ok and then got invited for on-site interview. 5 rounds in a day, 45 minutes each. with 1 hr lunch in between. I had to write code on white board for all of them. I think it was really difficult and plus the jetlag it was really exhausting.
Interview questions [1]
Question 1
use mutex and semaphore to implement producer-consumer problem
The process took 1 day. I interviewed at Google (Mountain View, CA) in Jul 2009
Interview
NDA makes this impossible to describe beyond - met with 5 engineers over the course of a day, each had a different technical/programming question. It would be easy for a recent grad or anyone who slings code 24/7. Not a good indicator of actual skills or abilities. Google interviewing at Google - there are plenty posted.
I applied through other source. The process took 1 day. I interviewed at Google (New York, NY) in Dec 2007
Interview
I had one recruiter call, then one technical interview over the phone (very nice question, very nice interviewer who guided me through the process of answering the question - he was very pleased in the end) then a short recruiter call (another HR person) then the on-site. There were 5 1:1s of about 30 minutes, with a lunch break.
The questions were easier than during the phone interview. A lot of coding. But I kind of blew up - I thought I had the right answer for some of the questions, but much later I realized my answers weren't great at all.