I've been contemplating hacking together some sort of Gvim-based interface
to the Ruby debugger, sort of a mini-IDE I suppose, that would do the
following, as a start:

* Use a split window to display code above, ruby debugger 
  interface below
* Do some pre-formatting and apply syntax highlighting to the
  debugger I/O (useful for "p"'ing deeply hierarchical objects)
* Synchronize current file/line in the code window to the debugger
* Define commands/keystrokes in the code window to do things
  like set breakpoint at current line, etc.

I'm by no means an expert with Vim scripting, but Vim features like :Explore
make me think it's a feasible project.  Please let me know any productive
comments -- pointers to existing work, suggestions to alternatives, public
demand for such a project, etc. -- that you might have.

Thanks,

 - jeff