Child Theme & php files?

I read this article about child themes <http://codex.ww.wp.xz.cn/Child_Themes&gt; and have a question.

I have a twentyten-child theme. I would like to add google analytics code to the header.php. RIght now have a copy of the header.php in the twentyten-child folder that has been modified with the code.

Is this the best way to handle this? Or can the code be injected similar to the way it was done with the functions.php example from the article?

TIA