Ahh, well this has come up in a couple of threads but apparently not in the FAQ section!

The Karma thing is just a fun little way to kind of rate people, nothing to be taken seriously if you happen to have a lot of smites :p If you see someone has made a post that you thought was helpful / nice / informative, then you give them an applaud! If someone says something mean or bad about someone's mother, then give them a mighty smite.

The "Windzio" thing under your name changes according to how many posts you have. But again, don't take it too seriously, it's no reason to go posting a lot! Quality over quantity definitely applies here :] Hope that helps!