For the Information Futures project we used Tagcrowd.com to generate visual representations of three documents — the Consultation Paper, the set of 70-odd written submissions, and the draft strategy. These tag clouds have been useful for showing the similarities and differences in what people care about.
Another such tool is Wordle.net, which can automagically make an even more aesthetically pleasing cloud of your wise and witty wordage. Here’s my del.icio.us collection of bookmarks, as seen by Wordle (click to see a larger version):
