How can I insert "raw" (X|XHT|HT)ML into my DOM?

I have an application where I have access to some Markup Language in 
string form. I would like to (effectively) insert that into my DOM as a 
single unprocessable chunk so that when I render my DOM, it get's 
rendered as HTML rather then as a TextNode.  The only solution I can see 
is to parse that HTML and insert it as DOM objects, and I really rather 
not have to do that.

Thanks for any tips.

David