For ideas on expanding your online opportunities, check out news of this recent announcement from YouTube, which allows nonprofits, for free, to overlay ads onto videos they post. (Don't have a video? This is a perfect project for a volunteer or intern.)
Or, look at what other nonprofits are doing on Twitter.
But don't forget the basics: A website that tells people who you are and what you do, with clear explanation of why you're a reliable and worthy place to send their money. For more information on this topic, see my article, "Using Your Nonprofit's Website to Help Fundraise," and this recent survey report about where nonprofit websites fall short.