If you don't have a DV camera but are running OS X you can connect your
camera to your computer via the USB port and capture streaming video
into iMovie.
Just try the directions below:
1. Launch iMovie.
2. Connect your Digital Camera to your computer by plugging the USB
cable directly into your computer. Do not use the USB port on your
keyboard.
3. If iPhoto launches quit out of iPhoto.
4. Click on the Switch to Camera Mode icon in iMovie.
5. Click on Record With Camera to capture video.
6. Click on Record With Camera again to stop recording.
7. Save your video.
8. Click on the Audio Tab in iMovie to record a narration or other
audio.