@kylek - Yes, it's possible - but apparently overlooked. I've added it to our development to-do list for the next minor update
@fishmaster - Glad you got it sorted out!
@Rafes - Absolutely. You'll find this option in the AddonChat AdminCP menu. It should be enabled by default. Popup links do require JavaScript, and if JavaScript is disabled users will be taken to the embedded page. The link on the main forum page next to the Who's Chatting list does link to the embedded page, but could be edited if you wanted to make it a popup link - I believe the link there is in the Phrases, and the popup link code itself can be found in the Templates.
@CrosseyedGamer - Good question. Right now, there is nothing in the plugin that accommodates this out of the box; however it wouldn't be too difficult to use the supplied AddonChat Who's Chatting code in a CMS block. Settings -> Site Integration -> Who's Chatting from your AddonChat control panel . Use the internal frame link method and copy/paste the code where you need it. This isn't recommended for heavy traffic sites, but should work for most. This plugin essentially caches who's chatting data such that users don't have to wait for a web service call to complete - the Who's Chatting link code in your AddonChat control panel is real-time.