Original author: Chris Biega.
On the current POC I have been working on, there was a requirement for Business Card integration with Confluence Wiki.

Wherever a name shows up Confluence, you can hover over the name and the option to view profile appears. When you click on view profile you will then see the business card.
This is done by modifying 2 files.
main.vmd
#if ($sitemeshPage.getProperty("page.spacename"))
$title - $webwork.htmlEncode($sitemeshPage.getProperty("page.spacename")) - #siteTitle() #else
$title - #siteTitle()
#end
#if ($webResourceManager)
#end
#standardHeader()
$!settingsManager.globalSettings.customHtmlSettings.beforeHeadEnd
macro.vm
Note: On 2.7.1 it's macros.vm and it's in /opt/apps/tomcat/webapps/confluence/template/includes
#macro (usernameLink $username)
#if ($username != "")
#if ($action.getUserFullName($username))
$action.getUserFullName($username)
$action.getUser($username).getEmail()
#else
$username
#end
#else
& nbsp; $action.getText('ano< wbr>ny mous.name')
#end
#end
After these changes are made, restart Confluence and you now have business cards with Confluence.