Ist rule of SEO [imho] is never say never.
With a bit of CSS those marquee's can look very nice.
Try this cobbled together/copied thing.
<marquee id="adsense" direction=up width=75 height=125 style="background-color:white;border:1px solid black">Adsense food here...</marquee><br/>
<a href="javascript
:adsense.start()">Start</a> | <a href="javascript
:adsense.stop()">Stop</a>
<script>
if (document.all)
adsense.stop()
</script>