Breakfast ideas please

[poptartpoptart]

This is not strictly a health question but here goes...

DS is 6 and at lunchtime and dinnertime he is a really good eater and eats a wide variety of food. However I am really struggling with what to give him for breakfast, particularly on weekdays. He has never really liked any sort of cereal, not even the sugary ones, porridge is a big no no and he also hates toast! I have been giving him breakfast bars (nutrigrain and similar ones) which he will eat, but he is getting fed up with the same thing each morning and I can't blame him. At weekends I am happy to make him scrambled / boiled eggs, a breakfast omlette, etc, but this isn't feasible during the week due to the ridiculous time we have to be up and out of the house for school / work. I gave him banana and yoghurt for awhile which he liked, but banana's tend to make him a bit constipated so I can't give him this every day.
Does anyone have any other good (and relatively quick) breakfast ideas please?

Throw a load of frozen fruit, yoghurt and oats into a blender, eat with spoon or add fresh juice to make a filling smoothie. Pancakes, croissants, muffins, crumpets, bagels?

Good quality muesli (not the ones full with sugar) with the juice of half an orange and yoghurt and a few grapes or blueberries. You don't need lots of muesli, just a few spoons as they are pure cereals and thus very nutritional. Given that he likes yoghurt he might not object to just a little muesli especially mixed with orange juice, yoghurt and grapes or berries.

Ds3 (5) has cheese or beans on toast (although he claims he doesn't like toast. Yogurt with chopped up fruit (strawberries, melon, pear etc.) I chop it up the night before and put it in a little dish in the fridge. Oatcakes and cheese. Cheese or bacon roll, bagel and peanut butter, something eggy or weetabix with chopped up fruit.