Did you know that Ryze doesn't allow you to delete your account on your own? You have to send them an e-mail requesting deletion, along with the reasons you don't want to be part of their network. Am I alone in being entirely creeped out by this stuff?
You'd think I would have learned my lesson already, but I also signed up for a LiveJournal account. The way they've separated your profile (personal info, interests, friends, networks) from your journal is simple and smart. The fact that your account auto-generates a FOAF file is pretty slick and I love clicking on one of my interests to see all of the other users and networks that share it. The primary limitation of LiveJournal as a platform for a learning portfolio is that you can't upload files to it, so you'd have to be linking out to documents, images and people outside the LiveJournal realm.