http://www.knowandnetwork.org/francesbell/weblog/78.html
Danah Boyd has blogged some good advice on online identities.
“Create a public Internet identity. I strongly recommend blogging, but even a homepage will do. Have a genuine all-accessible identity online that you’re cool with grandma and your boss reading. Don’t make it uber drab, but do provide context for who you are, what you do, [...]