For awhile I was addicted to taking pictures for the LJ community color_theory. You can see my posts here (all 101).
I tried to always focus on color relationships but not always on the same ones. This was a very positive challenge for me. Prior to joining that community I had no real goal ever. I've since lost interest in the community for a variety of reasons (i swear it has nothing to do with the fact people post black and whites) and am aimless again.
But ... I thought I'd highlight the few that I'm especially proud of. :)