One of the tips that was given in The Dinner Diaries was to mix nutritionally-lacking foods with nutritionally-superior foods to make the good foods more appealing to children. The author would make a trail mix that mixed the "bad" foods that her kids craved with the "good" foods that she wanted them to have. A very simple concept, but not one I had really thought of before. I've hidden vegetables in cookies and that sort of thing, but I had never put the good stuff in plain view of my picky child before. I tried it recently with my son, and it worked!
Here's the trail mix that I made recently for Ben: a handful of Reduced Fat Cheez-Its (HFCS-free, of course), a handful of almonds, and a handful of roasted pumpkin seeds. He really enjoys this trail mix and asks very specifically for it as a snack. Best of all, it's packed full of good fats (including wonderful Omega-3 fatty acids), vitamins, and minerals thanks to the nuts and seeds! And, it's fluid. I can change the mix to suit his ever-changing mood, and since his food likes seem to change daily (and sometimes by the minute), that's important!
If you have any suggestions for a healthy but kid-appealing mix, let me know! Sometimes my mind gets stuck in a rut and overlooks great combos.