Kanye West -- In and Out of Police Custody in 49 Minutes

Kanye West slinked into a police station for less than an hour Thursday ... when no one was looking.

Kanye was booked in connection with his misdemeanor battery case ... for beating on a photog at LAX. He pled no contest earlier this month and was required to turn himself in for booking.

So Kanye -- and his crafty lawyer -- chose yesterday at 4:30 PM. He went to the Hollywood LAPD station and got his mug shot taken and then got fingerprinted. It took a grand total of 49 minutes and he was out.

Kanye has to keep his nose clean for 2 years and also has to attend 24 private therapy sessions for anger management.