I have spent weeks on trying out dd-wrt, tomato and the others that would run on my router. I had a very simple request. And in my opinion the #1 missing feature in all routers. And that is to quickly and easily drop (and undrop) ip's / sites at the router level.
Tomato so far is superior because it "DID" allow me to see my traffic in a way that was easily understandable. I was able to copy/paste the offending websites/ip's that crossed my screen (in the router page) and enter those into access restrictions. It was tedious but it worked.
What I am proposing is that you already doing this technique in a number of places. Simply allow clicking on these sites, to automatically get entered into the access restrictions list.
And if the user realizes that the site was important. He should be able bring up a dropped connection page. and click on those to un-block those.
Since the router page is already a fairly responsive web page. It would be the equivalent of a nice peerblock, except this would be far superior because the router is the only device in the system that can actually block everything on all computers.
This would be incredibly powerful feature if implemented.