I did at a previous job. It was a small web development shop owned by a husband and wife, and around 7 employees. I was the lead developer there and getting bored with the work. I proposed that I work 3 days a week, Monday, Wednesday, Friday, and be paid 60% of my salary. I spent Tuesday and Thursday working on my side projects.
Eventually the company went out of business, but I had great success with working part time.
Eventually the company went out of business, but I had great success with working part time.