Here is another utility application I have put on Google App Engine – http://mytagclouds.appspot.com/. I wanted to check out how persistence and security works in an application developed for App Engine. Another thing I wanted to check out was how tag clouds are implemented.
This utility allows you to enter items, categorize them and then label them with tags you want to remember those items with. For example, if you want to maintain information about the movies you know, the books you have read, you can create categories called Movies, Books, and then start adding information under books and movies of your interest and easily navigate through the popular ones using the tag clouds that get built up.
Here is the accompanying article I wrote on DZone discussing its technical details.