No offense, but I don't think its very reasonable to expect a gleaming clean house when you have kids. I mean, us kids mean well, but we don't understand why tidiness is so important to you :D!
Seriously, I'm turning 16 in september and when I was little I could never understand why adults cared about tidiness so much. As I got older (around 10--12) I understood how much better it felt to have a tidy room, and I would clean it up myself every once in a while. Even then I was very aware of my surroundings and the way things looked, and I realized that I always felt more relaxed and comfortable when things looked good. Obviously the occasional fort making and silly-string fights and sudden creative inspirations which involved a certain amount of permanent glitter paints and a number of sadly ignored newspaper work areas are normal, but I think it's best to not sweat the small stuff.
I think a big thing is that many parents are very negative about messiness. Like, parents will complain about messy places and messy rooms, but do your kids really know why it bothers you so much? Have you ever told them? Going into a room and saying "Oh god, why must my house be such a mess?" does not exactly make your kid feel very enthusiastic, or very happy. Maybe you should try talking about how nice it feels to have a clean room, rather than how terrible it feels to have a messy room?
I seem to remember getting really annoyed when my parents asked me to clean up, because I considered myself to be a very clean little girl and I thought it was unfair of them to ignore all the good work I had done, just because my room was messy TODAY, when it had been perfectly clean LAST WEEK. I think I would have liked it if my parents had said something along the lines of: "I know how good you usually are about cleaning up, but today company is coming over and I would like the house to look really nice. Work your magic and get your room looking as sparkly as it usually does!" it may be a little unrealistic, but I always said to myself, "If they were just a little nicer about it, I wouldn't be so upset!!". After a while, they started doing that sort of thing, and while hormones and such still take advantage of me a little bit, I am usually much more cheerful about cleaning up.
Another note, having a pretty bedroom helps as well. We were pretty poor back then, but I remember that the first thing my parents did when we moved into our apartment was paint my room pink and glue huge life sized cut-outs of Snow White and the Seven Dwarfs on my walls. They painted my (second hand) bed white, I had a brand new duvet cover (purple flowers), and I got a mosquito net (for decoration) for my birthday. I thought that my room looked like a princesses palace, and it ruined the effect to have clothes lying all over the place.
This trick still works on me now. The first thing we did when we moved into our new house was paint my room dark blue, rip up the old carpet (hardwood underneath, yay!) buy a (brand new!) black iron bed, new duvet cover (blue with gold spirals), a pretty chair (blue), pretty curtains that drag on the floor and an antique mahogany desk with matching chair. I absolutely HATE having my room messy. I am now tidier than my father, and that is saying something.
Just a side note, ALLOWANCES HELP A LOT. TRUST ME.
So yeah, I don't pretend to be Dr. Phil or anything, but I always think that a little perspective of someone who is still quite close to childhood helps parents, just a little bit. It would help me if I got some perspective as to what the heck adults are thinking!! :D