Yes, you can! To recover deleted posts, visit this link:

http://edit.xanga.com/trash.aspx

Here's what you do:

1. Log into your site
2. Visit the Trash link.
3. Scroll down until you find the entry you'd like to recover
4. Click the checkbox to the left of that entry
5. Scroll to the bottom of the Trash page
6. Click the pulldown that says REMOVE and select the RESTORE option
7. Click the ENTER button to the right of the pulldown.
8. That's it! You can visit your regular private page to make sure your entry has been restored.