The stats page lists the 15 states with the highest number of declared LiveJournal users. For each state, here is the number of declared LiveJournal users in that state divided by the population of that state as of April 2000, sorted in order of largest ratio to smallest ratio. I did this because I suspected that Massachusetts would be the highest, and indeed it is.

MA - 0.003895
WA - 0.003160
MI - 0.002762
NJ - 0.002206
VA - 0.002192
NY - 0.002044
CA - 0.001985
FL - 0.001947
PA - 0.001878
MD - 0.001865
OH - 0.001533
GA - 0.001471
TX - 0.001269
IL - 0.001187
NC - 0.001161