I am not a huge fan of the "personal brand" sentiments. Something about pushing yourself on people rubs me the wrong way. That said, I do really like the idea of controlling your own identity online. After all, if you don't own it, someone else will!
In the past I have used iWeb and .Mac to compile a list of all of my internet profiles. The challenge was remembering them all and keeping up with the static page. Google has recently introduced Profiles ( Google.com/profiles) where you can claim your identity across the net. It appears that the more your tell it, the smarter it gets. Start with creating a profile and linking to your homepage or twitter account. Pretty soon google starts finding other sites on the net that appear to belong to you - facebook, flickr, vimeo, etc. Additionally, when someone searches for your name, your google profile will appear at the bottom of the search results. That means the likelyhood of someone finding the real you is much higher.
Not only is Google Profiles a great way to control your presence online, it is a powerful aggrigrator of our online selves. Take a look at mine - www.google.com/profiles/nickpdawson and you'll see what I mean. Things get even more fun when you use a vanity domain and point it to your profle. In my case, I have used NickDawson.ME which redirects to google profile. A profile and a .ME domain is an easy way to share your online contacts with anyone. Imagine creating a business card with nothing but your .ME address. "Want to reach me, here is a one stop shop".