The Face We Show The World

What  face do you show the world? I was thinking about this the other day, as I was trying to remember yet another password combination for one of my "online identities." Most of us have the "work" face, or personality, and then perhaps another "face" that we use with personal friends and family. Those are often two very different roles, and they can require different facets of our personality.
But what if it goes deeper than that? I use my "real" name on Facebook, and I have friends from work, from church, my parents, my kids, and others who know the professional and personal sides of my life. But I also have a Twitter account with just  a username - and I use that account for most of my contacts with friends and acquaintances in the publishing world, who don't know me in "real" life. I wouldn't necessarily want my boss or my pastor (or my parents!) on my Twitter feed....
I have a blog (in fact, I have three), and each of them involves a separate facet of my life -- I use this blog to comment on random thoughts, politics, life, etc. Mousegal's Dreams is a family oriented blog, and I post pictures and personal thoughts. And StarryEyedTravel on WordPress is a travel commentary, leftover from my days as a travel agent. I should do more with that blog, and perhaps someday I will.
I have no problem keeping all of my "identities" straight, but it bothers me sometimes when I am commenting on someone's blog, and I realize that they only know me from an email (ladyb67) or Twitter (Mousegal) and now I'm leaving a comment with a Blogger identity, which will be completely different. I briefly thought that I need to create some sort of master signature, listing all of my sites and screen names...but wouldn't that defeat the purpose?