amung.us said:

IMPORTANT: hosted WordPress blogs (ie. you have a site like http://yourblogname.wordpress.com) require a slightly different code and the map widget can not be embedded directly in your blog. Contact whos.amung.us for the appropriate code for your blog. If you run your own WordPress installation the normal widget codes will work fine.

so you cannot paste code directly to yourblog.wordpress.com, please consider use this way.

Step 1.
get code from http://whos.amung.us/showcase/
pick one,i.e. The small widget.
Double click and Ctrl + C

you got this:

<script id="_wau2ud">var _wau = _wau || []; _wau.push(["small", "9yuhqjikxxx3", "2ud"]);
(function() {var s=document.createElement("script"); s.async=true;
s.src="http://widgets.amung.us/small.js";
document.getElementsByTagName("head")[0].appendChild(s);
})();</script>

take a look, the “9yuhqjikxxx3” is your tracking code, simply paste this modified code on:
Wp-admin > Apprearance > widget > Text

code:

<img src="http://whos.amung.us/widget/9yuhqjikxxx3.png" border="0" alt="hit counter" width="81" height="29" />

that`s all.