Change your catalog template in magento

It is very good idea to change catalog template
it control from catalog.xml of your theme folder open it and find this code
<catalog_category_default translate="label">

<label>Catalog Category (Non-Anchor)</label>
after this code add this
<reference name="root">

<action method="setTemplate"><template>page/2columns-right.phtml</template></action>

</reference>
if you want to change your template into 2columns-right