Twitter is all the rage right now -- it's the easiest, quickest way to let anyone interested know what you're up to, and because it's so popular, it's also no surprise that we've seen quite a few Twitter and World of Warcraft mashup apps. wowTwitter is a separate update service just for news about your characters, WoWHorn is a script that lets you Tweet when you hit certain achievements, and though services like PlayXpert have let you Twitter from the game before, TweetCraft appears to be the first standalone application designed to do just that. After installation, it works the same way as an addon, though it's actually not -- addons can't directly connect to the Internet, so TweetCraft instead uses an outside script to read and write tweets into settings files, which the ingame addon then reads to get and send your tweets. It gets complicated, but you don't need to know all that to install and use it -- when you run the setup app, it'll put everything in the right places for you.
As with all third-party applications, you should install and run this one at your own risk -- the FAQ has more information if you're wondering how things are stored or whether the app is secure. The app is completely open source, which means anyone who wants to can read the code, so if the author of the app was doing anything sneaky, we'd know about it. And yes, right now the app is not violating the ToS, but of course that's enforced according to Blizzard's whims, so again, use it at your own risk. If you're not interested in using this app, you can always update your status here on WoW.com using our own addon -- it's not Twitter, but it will let your friends keep track of you in Azeroth!
But TweetCraft does look to be a clever, solid way to access and post to Twitter from right inside your World of Warcraft game. If you've been looking for a one-stop solution like this, there you go. Do be sure to follow us over on Twitter, too, if you haven't yet -- you never know when we might tweet something you'll want to see.
Update: Apparently the app on default tweets all kinds of things you probably don't want to (like changing zones). There is probably a settings switch somewhere, but as always, user beware.