It's an interesting question, I could say Gmail or Twitter but it only makes me happy when I receive an interesting Email or IM, so in that case is not a bout t

It's an interesting question, I could say Gmail or Twitter but it only makes me happy when I receive an interesting Email or IM, so in that case is not a bout the software but the people. The only software that makes me happier are music players (Exaile, Amarok, etc) because they let me hear the music that I love in my PC.