speaks to a particular audience, weed out the leaders of each category and make them aware of what you’re doing. Use Technorati to find the most prominent bloggers in these categories, and approach them personally and individually, offering them your content and/or reciprocal links.
Find every event site related to film, digital media, arts & culture, as well as the city where your event will be hosted. Create a reference sheet containing your event’s title, a short description, a long list of comma-separated tags, a shorter version of the same list, and other pertinent information which will need to be standardized across all submissions. Put on a pot of coffee and hammer away.