Jessica Biel & Justin Timberlake Hook up at Sundance!

Jessica Biel flew out to Sundance to spend time with Justin Timberlake, sources reveal to PerezHilton.com.

"Justin is in the middle of his tour right now," says a Timberlake source. "But he's planned his time in Sundance meticulously. He's been there since Saturday, even though his movie, Black Snake Moan, didn't premiere until Wednesday. His whole family, including his mom (who celebrated her birthday with him in Vegas on Friday), has been with Justin in Park City while he took this mini-vacation."

Now that Jessica has ended her relationship with Derek Jeter, she heated things up with Justin in Sundance writes Perez Hilton

"Jessica was picked up in her chauffeur-driven Volkswagen Touareg car and instantly went to visit Timberlake when she got into Park City," says a source.

A few weeks ago, Cameron Diaz and Justin Timberlake split because the singer cast Scarlett Johansson in one of his music videos, it has been claimed.

Cameron - whose four-year relationship with the SexyBack singer came to an end shortly before Christmas - was allegedly furious when Justin chose
Scarlett to play his love interest in the promo for his song What Goes Around.

The couple's relationship was already struggling and Justin's casting decision was the final straw. A source told Heat magazine: "When Justin cast Scarlett,
Cameron felt it was the first time another person was involved. She can get very angry and very jealous.

"When she knew the other person was possibly Scarlett, she was furious. The two women have never been good friends, plus Scarlett had a relationship with Jared Leto, who Cameron had previously dated for four years."