I think if you took all that open green space in the top header bar and fitted it with a window to run 24/7 streaming hardcore porn, or professional midget tossing, I know I'd spend more time on the site...
On the serious side, my thoughts on the visuals...
* I'd probably take a graphic of one of the less intricate Celtic knots, and run it left of the kilmurry.net text.
* If you have the flexibility, take a smaller version (or another graphic of an even simpler round knot) and use those for the topic bullet graphics (currently the little green apples).
* Take the text for your top global nav bar and either make it a little larger or use a bolder font. As it is, it disappears a little.
* Add some other colors to the page, preferably black or a darker color, to set off the green. I love green too, but right now the color fade you're using could only be described as "pistachio muzak." Ask Ebon for 30 seconds of his time and he'll cure all your color ills...
I think doing some of those things would make your forum pop the eyes a little bit more...but I like the idea...nice concept for a family communication center.
Edited to add: I like this picture below as a modern way of representing the celtic grid knotwork of the old days...
image courtesy of Steve Abbott
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