Regarding Syntax Highlighting, Daniel Turini pointed out that SnippetCompiler has the ability to export code to the clipboard (and to a file) as HTML.
Snippet Compiler has a lot of nice features and is a welcome addition to my toolbox, but purely for syntax highlighting, it has a few disadvantages compared to the manoli.net website I mentioned previously. First of all, although you can view snippets with line numbers, the line numbers aren't exported to HTML like Manoli does. Secondly, Manoli handles XML/HTML along with C# and VB, while SnippetCompiler seems to do well only with C# and VB.NET. Lastly, Manoli uses CSS for styling and you can have it embed the CSS definitions in the generated HTML, or reference the provided stylesheet. This is a really nice feature.
One thing I do like about the SnippetCompiler is how the summary tags in the comments are gray while the actual comment is green. That's a nice touch.
///Manages cool things
public class ThisIsSoCool
/// This is seriously neat.
public void YouShouldTryThis()