I just found http://worditout.com/ . Although it does not have the ability to choose the form of the word cloud like tagxedo, you still have color and font choice.
To make a word cloud for the iPad, I created a word cloud on the site, then I took a screen shot of it and cropped it in skitch. I was able to select a photo from my photo library for this blog--no need to "select a file" ( the death knell for iPad uploading because you can not choose a file in iPads). Voila word cloud for iPad!
1. Have students do an about me cloud - they need to type their name about 10 times for their name to be larger than the other words
2. Speech analysis
Have students copy and paste a speech into the word cloud to help them identify theme words.
3. Writing revision
Have students copy their own writing into the word cloud generator and see which words are most prevalent. They can then edit to eliminate high frequency words for meatier ones.
Here is a live binder with lots of other resources http://www.livebinders.com/play/play/3017