I found a plugin called indent guide that produces a left scope indentation guides similar to intellij. I tested it and it works perfect with Juno. You can install the plugin through Help -> Install Software, then add http://atlanto.github.com/IndentGuide/update to work with. That’s how my eclipse editor looks now:
** Update: Lots of people come here searching for the scope lines. Seems that the projects above are no longer there.