This is what DailyOM had to say about keeping a diary. For me, Xanga is a diary, just a little more public.
Keeping A Diary With Purpose
A diary can play many roles. It can be a confidant, a vehicle of self expression, a tool that facilitates clarity of thought, or a repository of dreams. A diary can also be a powerful source of comfort during challenging or traumatic periods. When you record those insights and incidents that clearly demonstrate you are on the right track, you can return to your words days, weeks, or months later and find uniquely soothing reassurance. A diary with a specific purpose can be a good tool for keeping track of experiences before the passage of time can skew your perception of events. It reflects the immediacy of your life and thus provides you with a landmark to return to when you begin to doubt yourself. If doubt does arise, simply open your diary to reaffirm your experiences. The confidence, surety, passion, and bravery you felt in a single moment is preserved, giving you a means to recapture those feelings in any place, at any time.