Slime mold on turf can be removed by raking, brushing or a blast of water, it's not a disease.
I've only seen it once and didn't do anything about it, it went away and hasn't been back since.
Ken's problem (assuming Nostoc commune?) is apparently a cyanobacterium (formerly considered an alga) that grows in colonies. I think I've seen it around here, especially on some large rocks.
