Capturing video output onto my mac

This is my first post. I don't do much in the way of AV stuff, but I'd like to capture the output of my baby video monitor (A/V outupt jack) on my iMac and maybe watch it on iMovie. I figure I need some sort of analog to digital converter, but I don't know which. The ones I've looked at seem like they're for converting VHS to digital and I don't know if they do real-time audio-video. Thoughts???

I'm pretty sure I answered this once already in another thread??

You want El Gato's EyeTV Plus.

Thanks

Thanks for your reply. I guess I didn't search the other threads well enough. That looks like what I need and it looks like Amazon has it for sale.