These instructions will move the block to to the centre under the product descriptions.

You can see this at work here on a <a href=”http://www.cl-floraldesigns.co.uk”>wedding flowers</a> site.
In catalog.xml find

<reference name=“right”>
<block type=“catalog/product_list_related” name=“catalog.product.related” before=“-”template=“catalog/product/list/related.phtml”/>
</reference>

Remove or comment out

<block type=“catalog/product_list_related” name=“catalog.product.related” before=“-”template=“catalog/product/list/related.phtml”/>

Change the following to include the above…

<block type=“core/template_facade” name=“product.info.container2″ as=“container2″>
<action method=“setDataByKey”><key>alias_in_layout</key><value>container2
</value>
</action>
<action method=“setDataByKeyFromRegistry”><key>options_container</key>
<key_in_registry>product</key_in_registry></action>
<action method=“append”><block>product.info.options.wrapper</block></action>
<action method=“append”><block>product.info.options.wrapper.bottom</block>
</action>
</block>
<action method=“unsetCallChild”><child>container1</child><call>ifEquals</call>
<if>0</if><key>alias_in_layout</key><key>options_container</key></action>
<action method=“unsetCallChild”><child>container2</child><call>ifEquals</call>
<if>0</if><key>alias_in_layout</key><key>options_container</key></action>
</block>
<block type=“catalog/product_list_related” name=“catalog.product.related” after=“-”template=“catalog/product/list/related.phtml”/>
</reference>

Note the use of after=“-” instead of before=“-”

You may need to restyle it depending on your layout.