Robert Downey Jr. is apparently set to join Todd Phillips' upcoming comedy "Due Date," which also stars Zach Galifianakis, who's currently onscreen in "The Hangover."

Michael Fleming over at Variety reported the news about the deal, which has Downey Jr. slip into the role of a soon-to-be father who finds himself embark on a road trip while trying to reach his destination before his baby is born.

Galifianakis plays the other guy, a slacker. Further details are kept under wraps at this point. Alan R. Cohen and Alan Freedland wrote the script, with Adam Sztykiel doing some revisions.

Downey Jr., who recently starred in "The Soloist," will soon be seen in "Sherlock Holmes." He just wrapped filming for Jon Favreau's upcoming "Iron Man 2."

Downey Jr. and Galifianakis together on the big screen sounds hilarious, don't you think?