The stock Integra rotors are 10.4 inches in diameter, and I believe the Prelude/ITR rotors are somewhere between 11" and 11.5" in diameter. The Legend rotor is the same diameter as the Prelude/ITR but a bit thicker.

Hate to link to that "other" board, but here's some good info:

http://www.honda-tech.com/zerothread?id=475568
http://www.honda-tech.com/zerothread?id=734560