Yesterday I was working with my good friend Marcel on our massive multi player mobile internet strategy game (mmpmis?). He had written an API that I recently incorporated in the game and he'd changed it on a conceptual level, so I had to redo a lot of work... not funny. But due to the collaboration support NB provides we could share the various sources and show in the actual code what we thought the other understood, how we wanted it all to work and after about 5 minutes we knew exactly what had to be done.
The chatting feature in NB was replaced by Skype, talking is soooo much faster than typing. The only thing we were missing was some 'free drawing' feature in the collaboration features, where you could circle something you want to focus on, draw lines and arrows to show where you want stuff to go etc. We needed a whiteboard in NB.
Marcel used to be an Eclipse guy, but more and more often he tells me "NB is really cool" or "This feature in NB is really cool". Collaboration in one of those features.