i've been successful with whole hard-boiled eggs (DD is simply fascinated by them), scrambled eggs (chunky enough to eat with fingers), tomato slices with cottage cheese. chilled melon and watermelon chunks are great in this summer heat, just cut them up the night before to keep things easier in the morning. cut strawberries in half and let him dip them in yoghurt...there are so many fruits out there, you just have to keep trying out new ones. but don't stock up on one he seems to like or he'll just decide to hate it tomorrow:-)
the key is to avoid working harder on your kid's breakfast than he does!
good luck