Recently I had an idea about a way to navigate through a tree that is quicker than the typical outliner. So over the past few days I did a javascript/prototype/scriptaculous implementation of the idea. Personally, I like the result, but before I spend more time on perfecting it and making it work on Internet Explorer, I would like to get opinions.

View an example here .
It doesn't work in Internet Explorer at the moment.

Is it a good/bad idea? I wrote the code pretty quick so there are probably some bugs and room for improvement in the implementation. If you see any obvious things, you can mention them here.