Weezu is a downloadable chat app that runs as an extension in both Firefox and Internet Explorer. Like some of the other chat apps we've covered lately, Weezu resides in a sidebar on your browser. It's a bit more graphical than some of the other extensions out there, and if you want something that's a little prettier than plain text, Weezu's for you.
One of the things that attracted me to Weezu was its eccentric interface, which puts you in several different locals and is completely skinnable. My favorite is the sea floor--if you had kids they'll likely enjoy this. When you're not interested in chatting, Weezu can be hidden. Settings and messaging commands reside on your "command module," which also houses your user avatar and chat boxes. Other users show up as floating heads, clicking on them starts up a chat right away.
Weezu is an interesting chat service. It's really simple to use and can be turned on and off at any time, but it lacks some of the ease of entry I've seen with the no-download chat solutions. You still have to install something, which might keep the casual user from committing. There also are not a whole lot of people using the service right now, which isn't Weezu's fault, but rather the design of any of these browser chat services that spread users out across the entire Internet. Weezu has several language localizations, the English one can be found here.