Source: http://feeds.gawker.com/~r/lifehacker/full/~3/OkOtAn2wofg/tagcrowd-creates-word-frequency-clouds
Whether you'd like to hunt down words you overuse or you're looking to turn text from your manifesto into word art, TagCrowd can create a simple tag cloud based on the frequency of words.
There are three options for importing text into TagCrowd. You can give it a URL, useful if the URL points to a large volume of text but less useful for making a word cloud based on a blog because it doesn't drill down through links. Alternately you can upload a plain text file with a 100KB size limit or cut and paste up to 3MB of text into the provided text box—no indication on the site why there is such a sizable difference between uploading the text and pasting it. Once you've provided your text you then tell TagCrowd what language the text is in and it will automatically ignore common words in that language such as articles, avoiding a cloud with a giant THE in the center.
You can set the maximum number of words as well as the minimum frequency. You can also have TagCrowd show the frequency number next to the word. If there is a specific set of words from your text sample you would like to be ignored you can create a custom filter list to prevent them from appearing in the cloud. TagCrowd is a free application, if you create a particularly impressive cloud share a screenshot of it in the comments below. Thanks Mike!