To see what people are tweeting about the website you're currently viewing, you can use a bookmarklet / favelet for your web browser, built using Kynetx Apps.
(For anyone not familiar with bookmarklets, just dragging it doesn't work with Internet Explorer: for instructions see what's a bookmarklet or favelet and how to install or add it, and how to edit a bookmarklet.)
Then, when you're on a web site and want to check out tweets about the site, just click the Sweetter bookmarklet and wait a bit (be patient, it can take several seconds) for a popup that shows recent tweets about the site or blog you're on.
Here's what it popped up on clicking the link for my blog.
As you can see, it's scrollable for viewing older tweets (there's a limit to how many it can pick up though) and the X is of course to close it. You can't resize or move it, just use the scrollbar.
It does seem to show some repetition of some of the same few tweets though, I'm not sure why.
A useful and fun tool, and it's free too - so no reason not to go get it!