What is the most convenient way to convert HTML to plain text while preserving line breaks (with JavaScript)?

Basically I just need the effect of copying that HTML from browser window and pasting it in a textarea element. For example I want this: <p>Some</p> <div>text<br />Some</div> <div>text</div> to become this: Some text Some text

[miya-jan]

DOMを文字列に変換する方法について。TextRange使うとこんなにスマートなことに驚き