<p>How about selling/giving away t-shirts with our logo/site url at conferences? See the following links for how mathoverflow does it:</p>

<ul>
<li><a href="https://mathoverflow.net/logo">https://mathoverflow.net/logo</a></li>
<li>See Anton's shirt: <a href="https://mathoverflow.net/users/1/anton-geraschenko">https://mathoverflow.net/users/1/anton-geraschenko</a></li>
</ul>
