On Skype, around 30 - 40 minutes. Interviewer was very friendly and gave a lot of info about the position, made a great interview environment. Not that many questions, was more of a conversation actually.
Internship applicants have rated the interview process at Spyderco with 3 out of 5 (where 5 is the highest level of difficulty) and assessed their interview experience as 100% positive. To compare, the company-average is 25% positive. This is according to Glassdoor user ratings.