I find myself looking over TED talks much more frequently now. With these TED talks, I believe that there really is not right way for our presentations to be presented as long as you can get the information across.
I actually tried the SuperBetter website a while ago (I have a little bit of a productivity apps addiction), it's a really neat idea, but it would definitely help to have someone be an "ally" to help keep you motivated, otherwise it's pretty easy to forget about.
Fitocracy is a really fun one for working out!
There are a lot of really interesting idea that I would have never thought of in these.