[BRotondi]

And perhaps this one is also interesting for some users: You can change the title of any php block by customising $this->blockinfo['title'] with any html code. Including images, links, ...

Here an example, how to use this for navigating: vbMediaWiki, Missiologie. with php-code

$f = $GLOBALS['foruminfo']['forumid'];
if ($f == 76) {
    $this->blockinfo['title'] = '<a href="forumdisplay.php?76-Missiologie.net-(fran?ais)">Missiologie.net</a>';
    $s = vB_Template::create('sidebar_missiologie')->render();
} elseif ($f == 70) {
    $this->blockinfo['title'] = '<a href="forumdisplay.php?70-vbMediaWiki">vbMediaWiki</a>';
    $s = vB_Template::create('sidebar_vbmediawiki')->render();
}
return $s;

Of course more automation is possible here. Only a first step.