I've got a Sony DVMC-DA1 (DVMC-DA2 is the current model), all it does is converts analog to firewire and back. It's great, but it costs almost as much as a cheap MiniDV camcorder. When I bought it, the camera I was using (Canon Optura) did not have Analog inputs. I've since replaced that camera with a GL1 which has analog in so it's now used mainly for Final Cut Pro previewing and for output to an SVHS VCR. A couple other companies are making converters now as well, I think Formac is one of them.
When I've got VHS/SVHS source material to capture, I dub it to MiniDV via my camera's analog inputs and then capture from the MiniDV copy via firewire. This allows frame-acurate captures (as acurate as MiniDV can be) and batch capturing. I'm not sure what application you're using though - if it's iMovie, batch capturing is not an option I don't believe. (I could be wrong, I rarely ever use iMovie)
I use the Sony Mini deck as well. I have the one with the large lcd display but the low end ones don't and you can get those for around $500-600. I find them to be great little devices, saving the wear and tear on your camera and having it permanently connected to my computer. I end up using it as a video display when I'm in FCP, very nice.
there are some cheep boxes that convert from analog to to DV and back the other way. You just hook it up between any analog source (like a VCR or a TV) and your Mac. And they are cheep too. under $100. I think there is one called "My Video" I saw it in a macZone catalog.