[Frosty]

Login to your Admin Control Panel, go to Styles & Templates - Your template - Select "Edit Templates" from the list, find "Postbit Templates" - click twice, open "Postbit" or "Postbit_legacy" - it depends on which one do you use.

Open the template and find:

PHP Code:

<if condition="$show['avatar']">
<td class="alt2">
<a href="member.php?$session[sessionurl]u=$post[userid]">
<img src="$post[avatarurl]" $post[avwidth] $post[avheight] alt="<phrase 1="$post[username]">$vbphrase[xs_avatar]</phrase>" border="0" /></a>
</td>
</if> 


Replace it with this:

PHP Code:

<if condition="$show['avatar']">
<td class="alt2">
<a href="member.php?$session[sessionurl]u=$post[userid]">
<img class="roundedav" src="$post[avatarurl]" $post[avwidth] $post[avheight] alt="<phrase 1="$post[username]">$vbphrase[xs_avatar]</phrase>" border="0" /></a>
</td>
</if> 


As you can see, the only change to the code was "class="roundedav"".

Now, save it... Go to "Main CSS" of your template, scroll down to the Additional CSS box, and add this:

.roundedav {
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;
}


Proof of concept: