Interesting story - friend told it to me, so I guess it could be urban legend, but as far as I know it's true.
My friend's friend was at a Grateful Dead concert a few years ago, and he and this other dude were sitting in their car with a small amount of pure LSD (crystal form) out on the dashboard. Cop comes along and busts them - he figures it's coke, so he does the old finger dip to the mouth thing. He tells them to stay there and walks back to his squad car. He didn't come back. Story goes he sat in his cop car and REALLY tripped. The Dead-heads estimated that he must have done 50-100 hits with that one finger tip dip. The moral of the story is know your drugs!!
But as this post relates to the topic, yea, I guess you could snort pure LSD, but wouldn't recommend it because you're dealing in such tiny amounts.