I've used these and they work well:

[Link: s-video.com]

They're passive & compact. Also, check out their other AV-over-CAT5 stuff:

[Link: s-video.com]

If you want an active unit, check out:



There are 2 separate models, one to transmit & one to receive. Here's its' manual:

[Link: audiocontrol.com]

I haven't seen one of these is wallplate form, I just attach the box to the wall next to an RJ-45 jack.