I’ve just installed iG: Syntax Hiliter.
Lets give it a go:

 for (i=0;i<10;i++)
{
out.println("Madonna Rules");
}

Now this is cool

Plugins are one of the reasons I really digg Rails. Essentially plugins let me do stuff without re-inventing the wheel. The fewer lines of code I write, the happier I am. I’ve always had a fascination with TreeMaps and could see the idea being useful in a few projects. With the acts_as_treemap plugin I can now immediately implement a TreeMap. Rob Orsini has posted a tutorial on getting up and running.
If you happen to be wondering what a TreeMap is and how it could possibly be useful as an information visualization tool: A picture is worth a thousand words.

Rick Osborne has published a nice series on handling hierarchies in ColdFusion on his blog. Even multiple parents are discussed.

JMAGE is very cool. It is a JSP tag lib that makes it very easy to do image processing. It has tags to resize, crop, rotate, brighten, darken, ovelay an image, add a background, add text, convert to greyscale, blur, detect edges and apply a lowpass filter. This could certainly be used to create a Web 2.0 service.