Here's the deal. Xanga has a premium level of service, for pay. If you want to connect with the insulated Xanga community, then you have to blog here, upload audios and videos here, use pulse, and as many of the modules and stuff that's here.
For those of you who connect with people in the open world wide web, through social networks like twitter, blogs on WordPress and/or Blogger, and so on, it takes more effort to connect into the "walled garden" social networks.
One of the ways to get content into Xanga (and many other web apps and social networks) is through email. And that's the opportunity to get Twitter tweets into Xanga.
From the Xanga help section, it says:
But, when you click on that link, it will tell you to upgrade to
premium. If you're already premium, good for you. If you have money to use for Xanga, then it's $4 for 1 Month, or $25 for 12 Month, of premium service. And that'll let you email to Xanga as a blog post.
And then, you have to find something that will take your tweets and send them into an email. And that email destination would be the unique Xanga Email Posting address.