Before we jump into the instructions on linking your Gizmodo commenter account with your Twitter account, it's important that you know that the feature doesn't auto-tweet all your comments but simply provides you a "Tweet this?" option when submitting a comment.
To set the feature up, you'll head to your commenter profile page and find the "Link to Twitter" button:
That will redirect you to Twitter where you'll be asked to sign in:
After signing into Twitter, you will be redirected back your profile page and be asked if you want to follow Gizmodo on Twitter (optional):
Once you've done that, you'll start seeing a "Tweet this?" option when making a comment:
If you mark the "Tweet this?" checkbox, then your comment will automatically be tweeted along with a link to where it was made. Note that this may take a minute to happen.
If you ever want to unlink your Twitter account from your Gizmodo account, all you'll do is head back to your profile page and select the "Unlink from Twitter" option.