11:15 AM PT -- Suffolk County D.A. Raymond A. Tierney just released a statement ... saying they appreciate Justin Timberlake's willingness to accept responsibility for his actions -- and to use his platform to increase public awareness of drunk driving.

He adds Timberlake didn't receive any special treatment because of his celebrity status ... adding justice should always be applied fairly.

10:10 AM PT -- The first photos of Justin Timberlake from inside the courthouse are out ... capturing the singer-songwriter as he and his lawyer Ed Burke Jr. handled the plea in his case this morning.

While he looked somber in some photos, he cracked a huge grin in others ... looking pretty relieved to put the whole ordeal behind him.

9:50 AM PT -- Justin is addressing the media outside the Sag Harbor courthouse for the court-ordered apology ... telling the assembled press, reiterating much of what he said in the courtroom. He says he tries to hold himself to a high standard -- something he didn't do in this case.

JT adds he could've made a different, more responsible decision, but he did not. He tells people not to get behind the wheel of a car, even if they only have one drink.

Timberlake thanks everyone -- from the residents of Sag Harbor to those in the courtroom to police on the streets -- for working through this process with him. He says he's going to do his part to end drunk driving, and he hopes everyone else can do the same.

9:44 AM PT -- Justin Timberlake has officially left the courthouse ... walking out quietly in front of numerous onlookers after pleading guilty.

9:07 AM PT -- The judge has officially accepted Justin Timberlake's plea deal ... and he will do 25 hours community service within one year, and pay a fine up to $500 and issue a court-ordered apology. The judge thanked Justin for all that he said and for speaking from the heart. His license in NY State will have a 90-day suspension.

9:04 AM PT -- The judge asks Justin Timberlake how the court can be certain this won't happen again ... and, he responds he can say with "the utmost honesty I won't be back here again" -- joking he doesn't mean Sag Harbor, 'cause he loves the city.

9:00 AM PT -- JT's saying he's had time to reflect on his actions and didn't live up to his own personal standards. He says he understands his platform, one he spent a life building.

Timberlake adds he's grateful for the opportunity to learn, and he should've made a better decision for himself. He says he was raised on a certain set of values ... and, this isn't it.

8:57 AM PT -- Justin has just confessed to consuming alcohol before his arrest and driving impaired. Remember, back in July, his lawyer insisted Justin was not intoxicated when cops pulled him over.

8:53 AM PT -- Justin Timberlake's court appearance is underway ... and, as part of the guilty plea, he's agreed to do 25-40 hours of community service, and he will make a public service announcement, presumably about driving while impaired.

Remember, back in the day, Justin and the rest of *NSYNC made a PSA about drunk driving ... so, familiar territory for the the star.

Justin Timberlake just arrived at the Sag Harbor courthouse to enter his plea in his driving while ability impaired case, and the pop star ain't smiling in the clip.

The singer-songwriter arrived in a navy blue sweater and brown-gray slacks, rose-colored sunglasses covering his eyes ... and, a serious expression on his face as he marched up the stairs toward his hearing.

There's a lot of shouting and yelling from photogs in the clip ... and, someone asks if he has a message for his fans -- though he chooses not to respond.

We caught up with Johnny Wright, Justin's longtime agent, outside the courthouse this morning ... but, he's staying tight-lipped on how the pop star's doing.

Timberlake's legal team arrived at the courthouse before Justin ... ready to show their support for the pop star as he finalizes this legal case.

Not everyone's in support of Justin though ... at least one protester -- holding a photo of a young boy, presumably killed in a drunk driving accident -- is hanging around the courthouse. It's possible she's protesting the plea deal Justin received.

TMZ broke the story ... JT plans to plead guilty to this lesser charge -- a traffic offense, a way smaller offense when compared to the original DWI charge, and then officially put this case behind him.

While Justin's charge has the word "impaired" in it, it's not a drunk driving offense ... and, we knew he'd only have to pay a small fine between $300 and $500 -- barely even a slap on the wrist for the mega-rich star.

Justin's driver's license is suspended In New York ... standard procedure for anyone who turns down a Breathalyzer like cops say Justin did back in June.

As we told you ... Timberlake was arrested on June 18 after cops say he blew through a stop sign and failed to stay on the right side of the road. Cops say he failed all of the field sobriety tests and ultimately arrested him -- releasing him the following morning.

Timberlake's had to enter his plea of not guilty twice -- getting arraigned a second time after his lawyers challenged the first set of charging documents because of some sort of error.

He's since changed his tune and decided to plead guilty to the lesser charge.

JT's cracked jokes a few times during his world tour ... mainly poking fun at himself. We'll have to wait and see if he laughs this guilty plea off too.