I met a deaf-blind man last weekend. He hadn't lost his eyesight until later in life, so he was fluent in regular ASL before that. To communicate with him, I just signed ASL and he felt my hands. Pretty amazing how he could understand everything without being able to see my mouth morphemes. I assume he was just very sensitive to how one tensed their arms and fingers.
I was fascinated. I'd like to train myself to understand tactile ASL so that I can communicate in the dark if necessary.