Win Some, Lose Some, Gain some

I have been a User of MFP and spark people before, though I never really used the community parts of either site. Here's my deal: I started at 220 lbs but over the past three years the lowest I've gotten is 170, 20 away from my goal. I sometimes gain a little back though I never reach my highest weight. This is the heaviest I have been in a while so thought I'd better get back on. the wagon. Has anyone else had this off again on again relationship with these sites? I'd like to know if you have any tips.