The IT Crowd's Chris O'Dowd is having incredible success in the US right now, thanks to a well-received role in Bridesmaids. Next up for the Irish actor is headlining a brand new comedy from renowned mockumentary-maker Christopher Guest (Spinal Tap, Best In Show). Family Tree will follow Tom Chadwick (O'Dowd) as he researches his unusual family history with the aid of a mysterious box he inherits from a great aunt he never knew. The series has been created by Guest and regular collaborator Jim Piddock, and will air on HBO in the US and BBC2 in the UK. Unusually, Family Tree has been commissioned on the strength of the concept and talent assembled, as a pilot hasn't even been shot. The comedy is expected to share a similar tone to Guest's movies.