Hi Patrick,
I believe that you are looking for a mod, but unfortunately I can't help you with that right now ..
What I can help you with is this:
First of all, sign into your Admin CP ..
Then, go to "Styles & Templates >> Style Manager" ..
After that, choose "Edit Templates" option from your defined vB Style drop-down menu ..
Then, Expand the template groups and look for either "postbit" or "postbit_legacy" template depending on what you use and edit it ..
Once you enter the template, look for:<vb:if condition="$post['signature']">
<blockquote class="signature restore"><div class="signaturecontainer">{vb:raw post.signature}</div></blockquote>
</vb:if>
Change it into this: <vb:if condition="$post['signature']">
<blockquote class="signature restore"><div class="signaturecontainer">
<vb:if condition="is_member_of($bbuserinfo, 1,2,3)">
<img src="IMAGE_SRC" alt="" border="0" />
<vb: else />
{vb:raw post.signature}
</vb:if>
</div></blockquote>
</vb:if>
Change the numbers in RED into the usergroup IDs you want and the text in GREEN into the image src you want ..
"Save" the template and go check the signatures :p ..If you want each usergroup to have it's own signature, you can use this code: <vb:if condition="$post['signature']">
<blockquote class="signature restore"><div class="signaturecontainer">
<vb:if condition="is_member_of($bbuserinfo, 1)">
<img src="IMAGE_SRC" alt="" border="0" />
<vb: else />
<vb:if condition="is_member_of($bbuserinfo, 2)">
<img src="IMAGE_SRC_2" alt="" border="0" />
<vb: else />
<vb:if condition="is_member_of($bbuserinfo, 3)">
<img src="IMAGE_SRC_3" alt="" border="0" />
<vb: else />
{vb:raw post.signature}
</vb:if></vb:if></vb:if>
</div></blockquote>
</vb:if>Don't forget to change the colored text as explained above ..
That should do the trick, and sorry again cos I can't help with an easier way ..
Good Luck ..