Xanga has fairly basic privacy controls. There's an option where you can limit viewers of certain journal entries to users in a predefined list, but Xanga Classic (the free one) only allows up to ten users on that list. LiveJournal, on the other hand, allows you to restrict entry views to your friends only, and there's no limit to how many friends you can have. I'm pretty satisfied with LJ's interface and ease of use.
Sophia's a pretty name! I go to a college named after you (well, no, but still). As for nicknames... "sophia... _mo"? I don't really do the nicknames thing well. My nickname comes from my agnostic beliefs in religion in general, which is usually personified by guardian angels (who protect and guide) as opposed to the scary, expecting-to-be-feared God. Sophia... "girl_of_wisdom"?