[ozzy47]

This should do it.

Remove the following code from the template MEMBERINFO:

<vb:if condition="$blocks[activitystream]"><dd<vb:if condition="$selected_tab == 'activitystream' OR $selected_tab == ''"> class="userprof_module" <vb:else /> class="userprof_moduleinactive" </vb:if>><a id="activitystream-tab" href="{vb:link member, {vb:raw userinfo}, "tab=activitystream"}#activitystream" onclick="return tabViewPicker(this);">{vb:raw activity_phrase}</a></dd></vb:if>

Then you need to set a new default tab.

To make Visitor Messaging the default tab:
Create a plugin at member_execute_start with the following code:

$_REQUEST['tab'] = 'visitor_messaging';

Or if you'd prefer the "About Me" tab to be default:

 $_REQUEST['tab'] = 'aboutme';