[plt-scheme] separate pane for (define ...) selector

One of my favorite features from Eclipse's Java editor is a small pane
that has all the classes and functions listed in order. Each class can
be expanded/compacted and clicking on a class or method definition
jumps the editor to that spot.

The (define ...) drop-down at the top of the DrScheme editor has the
same functionality, but it's not quite as convenient, since you have
to go to the menu and then find the name. Has anybody written
something that does what I'm looking for? I glanced through Planet,
but wasn't sure what to search for.

The Contour pane is similar to what I want, but I'd just like the
define lines to show up and be clickable. Being able to sort
alphabetically would be great, too.

If it doesn't exist, I might take a stab over the summer.

Todd