Turtleneck Company: We're Using Steve Jobs to Fight Cancer!

Steve Jobs' shrewd fashion sense could soon save lives -- TMZ has learned, the company that manufactured his favorite turtlenecks now plans to donate some of their proceeds to cancer research ... in his memory.

A rep for St. Croix knitwear tells TMZ -- starting today, the company will donate $20 to the American Cancer Society for every black mock turtleneck they sell. The offer expires next Thursday.

Unfortunately, the sweaters don't come cheap -- Steve's long-sleeved turtleneck of choice runs $175.

In other words, if you plan to pay tribute to Jobs on Halloween ... you better start saving up now.