From vbulletintemplates.com ...using search "Opacity" in all forums..and did a little quick writeup..
Code:
<if condition="$onlinestatus==0">
<if condition="$show['avatar']"><td class="alt2"><a href="member.php?$session[sessionurl]u=$post[userid]"><img src="$avatarurl" alt="<phrase 1="$post[username]">$vbphrase[xs_avatar]</phrase>" border="0" style="filter:alpha(opacity=10) /></a></td></if>
<else />
<if condition="$show['avatar']"><td class="alt2"><a href="member.php?$session[sessionurl]u=$post[userid]"><img src="$avatarurl" alt="<phrase 1="$post[username]">$vbphrase[xs_avatar]</phrase>" border="0" /></a></td></if>
</if>
For some reason, it wont work..but the opacity bit works..figure out the if statements and your away