I applied in-person. The process took 1 day. I interviewed at Costco Wholesale (Houston, TX) in Jan 2013
Interview
Incredibly easy and casual. Walked in to the store dressed business casual with my resume, talked to the General Manager for 10 minutes or so. He asked me a few standard interview questions (What have you done, why do you want to work here, etc). Gave me an offer right away.