Getting Viral
If you want people to find you randomly on the web, getting "viral" is the answer. It's basically getting your portfolio out there through word of mouth on speed. How does one get the initial jump-start for their work though? There are many ways to do this, but I have two favorites that you should learn about.

StumbleUpon - http://www.stumbleupon.com/

Stumble Upon is an upcoming web application with over 4 million users (and growing) that is quite unique. Basically you download a toolbar to Firefox or Internet Explorer that allows you to "Stumble" things. Users mark off things that interest them so when they click stumble they can be taken to pages related to graphic design, film, editorials, etc. When each user visits a site anywhere on the web they can click "I Like It!" The more users that click it, the more traffic you will get. People can also write reviews on each site - the more reviews the better for getting people to see you. I really suggest stumbling your works and getting friends to. This will certainly help pass the torch around the net. If you are the first person to stumble something, you "Discover" it. Make sure to vary what cool sites you discover, or you could be counted as spam, and no one wants that.

Digg -http://www.digg.com/

Digg is one of the most popular websites on the web. If you are unfamiliar with Digg itself, you may know of sites just like it. Users sign up (takes 30 seconds + e-mail confirmation) and can then "Digg" anything on the net. They break things down into Article, Video, or Image. The faster you get more Diggs the better. Getting about 10 Diggs in an hour can boost you to the "Upcoming" page. Getting about 40 Diggs in 20 hours can launch you onto the "Popular" page. If you're popular enough, it doesn't matter if you have 70 or 700 Diggs, you can make it on the front page. Beware though, not all Diggs are equal. The more sites you Digg that become popular increase the amount your Digg counts. So try to Digg only what you think people will also Digg.