The Young Man of Providence. This dramatized documentary from 1981 delves deep into the authors tortured genius. Suitably eerie soundscapes accompany readings from various letters and classic stories from the Lovecraft canon. I found this recently on t'Internets and thought it was worth posting as a companion piece to the above post, which comes direct from the t_ape archives. The audio quality is not of the highest, but it is quite listenable and the programme itself is first rate.
"Cthulhu lies dreaming"