As I write this, one of the hottest web tickets (besides Spotify!) is Google+. Both share in common the fact that you have to enter by invitation, giving, initially, a sort of exclusive feel. Most people who want to be on Google+ have by now made it in, though Spotify is just a few days extant in the United States and is still highly coveted. Both are interesting, and I'm enjoying using both of them. However, since I have only used ...