I think the reason that I like it so much is that I can see faces of people with whom I talk and from that I can judge better the mood in which they are.
For example Ann on this picture (taken during our last skype conversation on 14th of May) is clearly worried with something:

I rarely see her that sad. The image of her that I keep in my head (and heart) looks more like this:

(This photo was taken during our last hike in Swiss Saxony, on the 14th of October 2006)
Today I also talked over skype with my father (and his wife). He can make me laugh as nobody else. I guess we simply have the same sense of humor. I wonder why ;-)
I was surprised to hear that he uses skype to communicate with his students. Is that a direction into which modern education evolves?
He also told me a strange story today that one of his (female) students to all questions during a written exam replied things like: I like sex, both in the morning and in the evening. I wear such and such underwear and so on. (Just to make it clear: my father does not teach sexual education. The exam was from ethics.)