How can I repeat a video at slow playback speed? Is there any way to repeat a video while it's playing in slow motion?

I tried using both QuickTime and VLC. I don't see a way to control the playback speed in QuickTime, and the problem with VLC is that when the video replays, it loses the playback speed setting.
You can do this with QuickTime 7. Grab a copy off the Mac OS X Install DVD.

Go Window-> AV Controls and change the playback speed. (Or something with a similar name)
Then View-> Loop for repeating.