Justin Bieber -- I Wanna Move to Atlanta Now ... It's Hip Hop Heaven

Justin Bieber is a fickle kind of guy ... we've learned he's now looking at homes in the Atlanta area because it puts him smack in the middle of a hip hop mecca.

Bieber's been in Atlanta since last week -- where he's been partying shirtless with Diddy -- and sources close to the singer tell us, he's fallen in love with the city all over again.

Bieber lived in Atlanta briefly when he first moved to the United States years ago -- after Scooter Braun signed him -- and his most recent trip has stirred up very fond memories.

In addition to Diddy, Bieber's been hanging with southern staples T.I. and Rick Ross -- and we're told he's already asked them about where to buy the nicest real estate in the city.

Added bonus -- Atlanta isn't the paparazzi hive that L.A. is ... and Bieber has been enjoying the extra privacy ... for now. (Of course, paps tend to go where the money is -- and Bieber's a walking bank.)

It also makes sense because we're told Bieber is transitioning into hip hop -- he's Bizzle now.

This does NOT mean Bieber is abandoning L.A. As we first reported, he's been looking at 20 acre estates in Hidden Valley ... around 20 miles from his current home in Calabasas.