No need for a special controller. SATA supports hotswap natively.
BTW this has been answered <A HREF="http://forumz.tomshardware.com/hardware/modules.php?name=Forums&file=viewtopic&p=94709#94709" target="_new">before</A>. That's one of the reasons these boards have a search feature.
<i><b>Engineering is the fine art of making what you want from things you can get</b></i>