Pueden usar esto:
Valid Flash example for XHTML 1.0 Strict
Código:
<object type="application/x-shockwave-flash" data="images/banner.swf" width="288" height="128">
<param name="movie" value="images/banner.swf" />
<img src="banner.gif" width="288" height="128" alt="banner" />
</object>
Saludos!!