It's been 3 days when I discovered the cool Black Belt Knowledge community and I already have the 3rd, orange belt in Java ;-). Yes, it is a long way to the black one, but with this post I want to express how absorbing is this site! My further experience with the site is great. You are encouraged to take new exams with funny attributes like a champagne when you gain a new belt or a milk to help your students (when you are a mentor). To get new exams I had to participate in beta questions - review and vote on couple of them and this is a perfect way to learn. The more points you get, the more influence you have (for example you can create new questions).
This is an excelent place to learn not only Java but also other technologies like frameworks or database stuff
I put a new gadget on the right panel with my current belt to be even more motivated to earn new blackbelt level :-)