Well... maybe. There are a couple of free tools (say, MissingMediaBurner) that are free and can theoretically burn a VCD from a proper disc image. And there are free tools for building a VCD from a proper MPEG stream (such as VCD Builder), and there are tools that will encode MPEG video (ffmpeg is the best, and although you can use it for free it is technically $15 shareware). Put them all together, and you can probably crank yourself out a VCD for free, though it might end up being quite a hassle.
Try a search for VCD on VersionTracker to see what's out there. I did notice a program called
MMT-EZ that claims to go straight from an iMovie project to a VCD, but I'd be a bit skeptical of it. Worth a shot, though, since it's free.
Post if you have luck doing this.