Umm, thanks both - especially MarkE19. Unfortunately I made the post while editing the video rather than looking at the camcorder and having since done so I see that:
i) It's not a 557 but a 357 and more importantly:
ii) No external mic socket
So I'll have to save my pennies for a better quality camera.
In fact, having done this I think the main things missing from the 357 (a cheapish DV recorder about 18 months old now) are:
decent sound
Manual focus
Manual zoom (the zoom motor makes a surprisingly intrusive whirring noise)
Picture quality is more than adequate, really.