Long distances relationship... Does it work?

I found out recently that a friend's girlfriend is going back to her own country after completing her study here. So, with no immediate plan to go with her, my friend got himself into a long term relationship. While the general consensus is that the majority of long distances relationships don't work, I have seen it work before. But it makes me wonder, does it really work?

I've seen couples who broke up even before one of the partners has to leave for a far fling country. I mean, is there some sort of psychological barrier in each and every one of us that tell us that distance won't work?

In the days of snail mail and very expensive IDD calls, that could be the case due to the long time between correspondences and the relatively short time on the phone. But nowadays, technology changes that. Email, MSN, Facebook, etc. is almost instantaneous and phone calls are cheap as (come on, Skype to Skype is free).

In the current technological trend, is long term relationship going to work? Or does human need the need to see each other, feel each other's embrace, and be physically close to each other?