There is a small error in the documentation for the <apex:componentBody> tag.

The example code for the custom component is the following:

<!-- Component: myaccounts-->
<apex:component controller="myAccountsCon">
<apex:attribute name="var" type="String" description="The variable to represent a single account in the iteration."/>
<apex:repeat var="componentAccount" value="{!accounts}">
<apex:componentBody >
<apex:variable var="a" value="{!componentAccount}"/>
<apex:outputPanel style="border:1px solid black;" layout="block">
{!componentAccount.name}
</apex:outputPanel>
</apex:componentBody>
</apex:repeat>
</apex:component>

The entire example works because you use "a.name" in apex:ComponentBody even though you should be able to pass in and use any variable name you'd like.  The lines that need to be changed to make this work are:

<apex:componentBody >
<apex:variable var="a" value="{!componentAccount}"/>

I've made the changes to make the componentBody after the variable tag and changed the variable name to that passed in via the "var" attribute in the component:

<apex:component controller="myAccountsCon">
<apex:attribute name="var" type="String"
description="The variable to represent a single account in the iteration." />
<apex:repeat var="componentAccount" value="{!accounts}">
<apex:variable var="{!var}" value="{!componentAccount}" />
<apex:componentBody >
<apex:outputPanel style="border:1px solid black;" layout="block">
{!componentAccount.name}
</apex:outputPanel>
</apex:componentBody>
</apex:repeat>
</apex:component>

Hope this helps anyone trying to use componentBody within custom components!

ps- Can you have components with custom Facets?

Parker