I applied through college or university. The process took 3 days. I interviewed at 3M (Saint Paul, MN) in Nov 2013
Interview
The process is fast paced and was done through a rapid recruiting event. Potential candidates were interviewed by the interested hiring managers and several senior scientists, other managers and by the Director. One has to also give a highly technical talk which was followed by a Q&A session. Overall, I found the experience to be very pleasant and was made to feel very welcoming.