AFAIK the only up to date data is available to institutions and not the public. The exchanges provide delayed data that can be as old as a month or more.
http://www.nasdaqtrader.com/trader/defincludes/nasdshortint_def.stm
Notice the publication dates at the bottom. Short int #'s are always almost a mo. old. Only dealers ( market makers or specialist) have this info in a timely manner. They are only required to report once a mo. Since the specialist has the whole book he has total knowledge of short int. in a stock. Market makers only know what their particular firm has sold short. Nice little edge at any given time.