Thanks to Frank Nimphius' recent entry on getting the current logged in user one easily can use the UIX EL to include this information in an UIX page.
Normally everybody puts this information where one wants. But there is a specified position by the UIX StyleGuide. Simply use the <userInfo> to put it at a specific position without worrying about the positioning code.
Example:
<userInfo>
<flowLayout>
<styledText test="${uix.bajaContext.servletRequest.remoteUser}" />
</flowLayout>
</userInfo>
Using the styleClass attribute also allows you to specify a predefined or sub-classed style.