I applied through a recruiter. The process took 12 months. I interviewed at US Marine Corps (Lansing, MI) in Jun 2009
Interview
Go to a recruiter, they take you to the MEPS office. They perform background checks and test you medically. You have to take an online test. Then you go to boot camp. Once boot camp is over then you have 10 days off and then go back to SOI. Then off to your trade school.
I interviewed at US Marine Corps (Camp Pendleton, CA)
Interview
Standard interview panel with company level chain of command, asking why you should be promoted. Then a few questions related to common Marine Corps knowledge, and a few pieces of uncommon knowledge. Not a bad process, but ensure you are squared away.