Wordle provides tag clouds for lists of words, web pages, or delicious.com tags. Once the initial tag cloud is created, you can play with the format until you get a visualization that you like. You can then save it into the gallery.
There is a wordle blog ("News" in the banner) which highlights some of the interesting ways you can use wordle - from printing on mugs to using to teach spelling in a classroom.
For all the fun you can have with wordle, there are a few shortcomings:
Having said that, wordle was created by Jonathan Feinberg in his spare time and was never meant to be a social media site - but I can't help imagine how much more valuable it would be if some of the standard social media elements were added . . .