O'Malley made the leap to the big screen as an astronomy teacher in the hit "Deep Impact" (1998). He followed with the leading role of a commitment-shy flower wholesaler in the indie "Above Freezing" (also 1998) and returned to supporting parts as an air traffic controller in the forgettable "Pushing Tin" (1999) and as a preppy cocaine addict in rehab alongside Sandra Bullock in "28 Days" (2000).