Passport to Web 2.0

Bubbl.us is a simple and free though mapping web application like that lets you brainstorm online.
Why use bubbl.us?
Because you can:

Create colorful mind maps online
Share and work with friends
Embed your mind map in your blog or website
Email and print your mind map
Save your mind map as an image
And it’s FREE!

 
Add a tag cloud to any site.
Tag Cloud from an RSS Feed
Make a tag cloud from any RSS feed, then add it to your blog or site
Tag Cloud Widget
Turn your favorite RSS feeds into a tag cloud widget for Netvibes, iGoogle, Dashboard, or Opera.
Tag Cloud from Search
Generate a tag cloud based on a search [...]