There's a lot of flexibility over colours, themes, fonts and directions. Users can also change shapes, aspect ratios, tightness of the words - no more ridiculous orphan words - skip words and so on. However, it's also possible to upload you own images or shapes and different fonts - tag clouds in your own handwriting perhaps? (Though you'd obviously need to create the font first).
Another really nice feature that I've tried to bring out in the screenshot is that the words can move as you mouseover them. They flip horizontal and fly out. This is going to be a great aid to teachers, who want to work through a tag cloud slowly for example. Microsoft Silverlight is needed in order to see the words 'dance', but you may well have that installed already.
Tagxedo has just become my word cloud maker of preference. Only one question - how on earth am I supposed to pronounce it?
This is the main work screen, using words from one of my webpages (no cut and pasting of a word page any longer!), with the word 'Advanced' that's flown out to the front for me. You can see the menu on the left.