Although it is possible to select an aesthetic pleasing set of keyframes with the browser, exact control over the camera path is sometimes difficult. This is due to the large time complexity of raytracing on the fly. An alternative method could be to have a more interactive application determine certain portions of the flight path.
I have an openGL based quaternion fractal explorer (qfe) that could be used for this purpose. The problem is that the browser is capable of changing more parameters on the fly than qfe. Most notably the parameter c can be changed just as easily as the viewpoint when raytracing. Qfe polygonizes the fractal in order to render, a process which is time consuming. Once polygonized, however, the fractal may be explored real time.
Perhaps a hybrid of these two methods could be used for easier keyframe control. If each of the programs were able to understand the same parameters, then a given keyframe could be viewed in each of them. Given this, a camera path may be visualized realtime provided it does not change certain parameters. A set of control points could be specified by the user and a cubic bspline interpolant generated from them for the camera path. The path could then be previewed realtime, giving nearly immediate feedback on changes.