Google Buzz!! (GBuzz) Yes thats a new Gmail feature or shall I say google's new product... This is one feature, if done the right way, I think Google can put social networks like facebook, myspace (is this still around??), Orkut (I still get a message once in a while.. like say once in 3 months :P) out of market. But of course there are quite a few challenges... this can be used only by gmail users until Google plans to role it out of Gmail, but again... Gmail gets 170million unique hits every month... that’s huge!!
GBuzz lets you communicate not just your status with your friends, customers and public but also share information, links, photos, videos all from gmail with a single click... No more do you have to go to picasa, youtube to share your videos.. you can do all that very much from your Gmail.
GBuzz has more to it, you can add your twitter, facebook and few other apps to GBuzz... you no more have to visit to check your wall posts on facebook or twitter for tweets... you can see all of them from your Gmail and even reply to them right from your Gmail... you can also write a new one!!
The option to communicate either privatly or publicly adds to the security of your data, I see it as a new Google Product rather than just a feature.