actually its true...
from wikipedia/amphetamine
this is what wikipedia lists as amphetamine's bioavailability for different method of absorbtion. so you would get 3 times as high by snorting than oral. just remember that adderall pills have fillers in then that can get in the way of absorbtion if snorted.
OP: Bioavailability is 75% oral, and for the record, I just checked wikipedia, and it didn't say anything like what you've indicated. And again, wikipedia is a great reference tool, but not everything on there is necessarily accurate. Staysedated, are you sure you weren't on Wookiepedia?