HandBrake now leverages the FFmpeg project so that it can convert video from all sorts of different formats, not just DVDs. This should make it the clear replacement for the recently discontinued VisualHub. For unstated reasons, Handbrake no longer has built-in DVD decryption, although if you have VLC installed it will use VLC’s libdvdcss and work pretty much the same as before. Despite the version number, this looks like a big upgrade. As far as I know, HandBrake is the easiest and fastest way to convert video for use on an iPhone.
Update: Ars Technica adds:
Jon Rubin, one of HandBrake’s developers, got in touch with Ars to explain the true reason behind the removal of the DVD libraries: “One of our developers works for a large company and felt more comfortable concerning his employment if what he did in his free time didn’t raise IP issues.…”