Yup. Take a look at blaugh.com, probably one of the best viral marketing sites I have come across. The traffic shoots up from zilch to 50+million page view in the span of 2-3 months.
Give something away for free (or a contest) and then announce it in the sweepstakes, contest sites, etc. There are some huge newsletters that go out announcing contests, giveaways, etc.
I found this today. A free eBook with some good info - but the most interesting part is the attempt to make it viral. I signed up - sounded like fun and "Viral" is such a great buzz word I couldn't resist.