4
The user menu is called from:
system admin-->Templates-->system-->system_block_user.html
You can call it like this:
<img src="<{$block.avatar}>" alt="" width="whatever?" />
Or something like this near the top:
<tr>
<td align="center"><img align="center" src="<{$block.avatar}>"></td></tr>
<tr>
Or see this post
Here