I admit it. I’m an outlining fanatic. I love About this Particular Macintosh and their great Outliner articles, and OmniOutliner is probably my favorite piece of software on for OS X. I was pleasantly surprised to find SproutLiner, an online only outliner that is free and very easy to use. It takes advantage of AJAX and does a great job at making a browser-based app very user-friendly and intuitive. Kudos to the developer.
If you’re interested, you can see all the WebServices I’ve discovered on my del.icio.us account. There are some fun things in there