These are all great tips and they work even for folks who aren't clinically depressed! I have a "joy moment" jar that I put stickies in reminding me of those fleeting moments (a coworker told me she and the engineers all love working with me; a friend thanked me for making her laugh, etc). I also do the walk motivation thing: go to a grocery store that is further away but still walkable, or the liquor store (well, not so good for depression, but you get my point).

Keep going! I have been there and these tips would have helped me a lot then.