From my research in the synthesis of LSD and LSD analogs, one can actually create a tartaric acid salt of LSD. The benefit of this is that it is much more stable than LSD. Tartaric acid is added to liquid LSD in a 0.1% solution to prevent oxidation.
So yes, in theory a powdered form of LSD can exist: LSD tartrate. I don't remember exactly how one would go about it, as I am not a fan of that synthesis. Too much expensive chemicals/equipment.
A story comes to mind of some people in America getting their hands on the said salt, snorting it up thinking it was Cocanine, and spending a lot of time in hospital. Apparently they each had about 1000 times the average dose each. ( 1975, Clinical Toxicology Volume #8 Issue #2.)
[ 28 April 2002: Message edited by: Fetish Jester ]