I agree Beloz and if we have guests or I'm not in the mood, a quick, bugger off ensures the proper power distance is maintained. I think sometimes I like it though, like you said, you can't blame them for trying. It would annoy me though if I had a dog that wouldn't leave me alone to eat - I think you need to be able to get space/respect when you want it.
Eye contact is how he will ask for something he wants that is mine when he knows he needs to tread carefully. For example, his toys all live up on the mantle piece where he can reach them but knows he can't without permission. Sometimes he feels like playing, and so he will stand between me and the toys and look between us - making it very clear what he wants. If I say ok, he will go pick one to play with. If I say no, he just gets on with life.
If there's something else he wants or that he thinks I'll be interested in that's more serious, I get either barked at or bunted. For example, when the cat was a baby I didn't want him going outside but he was amazingly cunning and escaped a few times without me noticing. Sammy would run to me and bark right at me until I followed him and led me to naughty Vasco. Other times he has done this because he wants to show me that there is a dog walking on the other side of the road that he would like to play with... He gets told off for making me get up for that kind of crap. Thing is, he does it so rarely and often it's something so important that I always go now when he raises the alarm like that.