Every once in a while I have the need to create a word cloud for a project. The problem with most web services that create them is that the resulting artwork is rendered as a raster image. Not very customizable.
JasonDavies.com has a fantastic Word Cloud Generator that offers the ability to not only customize the appearance of your word cloud, but download it as a SVG file which you can open and further customize in Adobe Illustrator.
You can use keywords found on Twitter, Wikipedia, or enter your own custom keywords to create the word cloud. Customization includes setting angles of words, font, and number of words. To download your word cloud in vector format, right click on the SVG Download link and choose to Save Linked File As (making sure to add the .svg extension if necessary).