If you happen to be rocking an HTC Touch Diamond 2 already – either you're outside the U.S. or are an impatient American who imported – there's a hotfix available that's really more of a hidefix.
See, there's a "Start Recording" option that, well, doesn't really work, and so this hotfix just plucks the option from the phone. That said, there appears to have been some progress toward actually making it work. The legality of recording calls varies depending on where you live, so play with caution.
Or to avoid temptation entirely, just apply the hotfix, which you can get here.