Legapp, totally with you. I am actually studying abroad this semester - I thought that would be a great way to beat the 3L blues. It is empowering being in a foreign city and not being in Ann Arbor dealing with all the daily stupid crap that goes on at the law school. I don't even have very much work here, but what I do have, I find myself not doing, and am here on the boards (which I haven't really been since a pre-1L) or watching youtube for hours.
Do yo have a fall break coming up? Maybe a visit to family and old friends is in order? When I hear from my family that they're proud of me and happy for me, that kind of motivates me some. Or when I get together with those friends who have nothing to do with law school and we laugh hysterically about what life was like in high school, that can help too. But 3L does seem to be a really terrible state of lack of motivation.
Your goals for the year sound great - I hope you find the spark you need!