Irish American film star Robert Downey Jr. is angling to appear in "How To Talk To Girls," the adaptation of a best-selling book by a nine-year-old boy giving advice about the opposite sex.

The book began as a school project for young Alec Greven, but it eventually roped him a major publishing deal, leading to three further lucrative and best-selling 'How To' books.

Susan Downey, the actor's wife, looks set to become a producer on the project, and is overseeing potential redrafts of the script, sources say.

Currently the 45-year-old actor is circling the project, meaning he has yet to commit, and meanwhile he's gearing up to appear in 'Oz: The Great and Powerful' with Disney.