UPDATE: Pratt was formally charged Oct. 28 with misdemeanor driving under the influence. She faces up to six months in jail and a $1,000 fine if convicted.
Stephanie Pratt has taken a detour from The Hills into the drunk tank.
The reality TV trainwreck was busted on suspicion of DUI early this morning after a night of partying.
A Los Angeles police spokesman tells E! News that Pratt, 23, was arrested at 3:45 a.m. in Hollywood and taken to Van Nuys jail. She was released around 10 a.m. Sunday morning after posting $5,000 bail.
Pratt and several Hills costars spent Saturday celebrating Holly Montag's 26th birthday at hot spot Empire.
Pratt attempted to cement her nonparty-girl status before heading to the club, tweeting: "its my sissy @hollymontags bday party! just finished dinner and going to Empire but im pretty tired aka yes i am the party pooper :("
Ironically, the Daily 10 correspondent echoed the same sentiments when E! News caught up with her last night. "I'm a party pooper tonight," Pratt said. "I got bad news this morning. A friend passed away in a car accident, so everyone needs to drive safe."
A witness says at around 2 a.m. Pratt, Montag and other partygoers headed over to Beso in Hollywood, where they partied for an hour. After that the group parted ways and Pratt took off in her own car.
Party pooper, indeed. We can't wait for this episode to air.
(Originally published Oct. 18, 2009, at 8:30 a.m. PT)
Steph will soon be making a fine addition to our Mug-Shot Mania gallery.