I applied online. The process took 2 days. I interviewed at Lab Four (Memphis, TN) in March 2010.
Lab Four's interview process is pretty thorough, but not quite as intense as some (e.g. Google, Goldman Sachs). They are truly trying to create a great work environment with a team of people who are capable and passionate about Lab Four's mission, so they are very selective about their hires.
Your feedback has been sent to the team and we'll look into it.