Sign up to Twitter with a catchy name, and then sign up to "Twollow" here you will get a 7 day free trial of their services.
Twollow allows you to add in 5 keywords to search other users and become followers of them. The idea is they will then follow you. This doesn't always happen, but will a great deal of the time. From there you can advertise to your followers.
If you're posting links use bit.ly.com to shorten your URLs
I suggest this be part of your online campaign, not all of it ;)