I admit it... I spend a lot of time on Digital Photography School forums. My favorite forum is Games & Challenges. Why? Well, G&C is the place people post photographs with common themes. In my experience, the threads in Games and Challenges has lead me to view other photographers' photos differently. I pay attention to detail, background and color more than I used. In doing so, I am learning to critique my work better.
An added benefit, the best one of all, is new friends. Although I read posts from several forums on DPS, Games & Challenges is the place I've made the most new friends. I guess the commonality of the themed threads brings people together in melting pot that bubbles up into new friendships.
If you are using any online resources for making your photography better... or just sharing your photos, leave a comment and let me know where you spend your online time in the area of photography. Hopefully, I'll see you over on DPS!