I applied through a recruiter. The process took 2 days. I interviewed at US Army (Midwest City, OK) in Mar 2011
Interview
Go to MEPS and take tests (medical, personal history, etc) Sit around and wait to speak one one one with military occupation specialty placement worker. After agreeing upon open position, sign contract, and go home.
They sit you in an old building and ask you about yourself and your medical history. Then they document all this info before they have you sign a documents and waivers.
Just go to your local recruiter and take the ASVAB. After completing OSUT, you'll become an infantryman (11B). You'll be assigned your unit upon graduating. Make sure to stay in good physical shape.
You express interest and they call you. You will have to answer some basic questions about yourself and take a placement test. Then you will be sent to a medical processing facility to do a medical exam.