Beth Massi has done something I know some of you C4F readers have been asking for. Beth developed a quick and easy way to query a web site with LINQ to XML. One of the commenter pointed out also you can do a HTML to XHTML conversion with this tool.
The trick to doing this is loading the HTML into an XElement, from there you strip out the unsupported XML entities, THEN LINQ the HTML to get the data you wanted.
Beth, the 15 minutes this took you just saved the Internet days of work on what I'd be would be a far more complex solution.