Recently, I've started following Zen Habits and have found it to be a wonderful resource. Leo has started a new forum for us Zen Habits readers and I've signed up--specifically to participate in the monthly challenge.
For the month of July, you pick ONE goal you'd like to maintain (daily exercise, reading, eating right, etc...) and there is a thread where you can check in daily with the other folks participating in the challenge.
My goal for July? An hour of German every day. Starts today.