Go to The People's Choice Webby website to register - it seriously took me less than a minute. After entering your activation code, select the "Year Zero" campaign from the "Select a Nominee" drop-down menu on the top-right (for a web-savvy site, its sure damn hard to navigate!).
Just to note: 42 Entertainment is nominated for two categories, so make sure to vote for both the "Year Zero: Interactive Campaigns" and the "Year Zero: Branded Content" categories. I promise this isn't as hard as it looks. Also, today is the final day for voting, so please take a couple minutes and vote.