Hello there! I'm Miranda Rensch, Product Manager at SEOmoz and lover of visual communication. Communicating visually is one of the most effective ways to explain complex concepts and relationships, and can be a great way to explain your services/products and create valuable site content. I often use diagrams and whiteboarding in order to communicate new features and concepts internally with my team.
I've compiled a list of tools you can use to create visualizations, or simply use to communicate visually with your teammates. Enjoy, and feel free to add your own suggestions in the comments!
Tools for creating simple infographics and data visualizations
Piktochart is a web-based tool that has six decent free themes (and a whole bunch more for the paid version) for creating simple visualizations. You can drag and drop different shapes and images, and there is quite a bit of customization available. You can also add simple line, bar, and pie charts using data from CSV (or manual entry). You can export to PNG and JPG in either print or web quality. Note that with the free version, you get a small Piktochart watermark on the bottom of the PNG / JPG downloads.
Easel.ly is another free web-based tool for creating infographics. You cannot create graphs using real data with this tool, but its really good for conceptual visualizations and storytelling. It has a beautiful user interface and the themes you can start with are gorgeous. The themes support many common purposes: map, flow-chart, and comparison/relationship graphing. This tool has the best selection of well-design objects (people, a bunch if icons, landmarks, maps, animals, etc.) and backgrounds that I've seen throughout this list of tools. Additionally, you can upload your own images with the free version. You can download a web-quality version as JPG. This tool is still in beta, but it seemed to work pretty well to me!
Infogr.am is another free, web-based tool with some really nice themes and a great interface for creating simple infographics. This option also allows you to create charts using real data. There are 31 chart options that offer some really cool displays, like a radial bar graph, scatter charts, bubble graphs, and map charts. You can also add your own images and video. When you're done creating your infographic, you can embed it on a website and publish it to the infogra.am site (I wasn't able to find a way to download). This app is also in beta, but again, seemed pretty solid to me.