Our two and a half year old lab is a very affectionate loving dog, but sometimes when we are playing with him he will get really excited run around in circles with his bottom down and his tail tucked under, the problem is that he will snap and jump at you while he's doing it, we have found that ignoring him and trying to walk away is the best way to deal with it, but this is not always easy as he is a big dog. Does this mean that we should not play with him at all I am worried about this and have found myself telling the children not to get him excited. As I said other than these mad moments he loves everyone who comes into contact wiht him.

I have labs, and yes thay are extemely good as pets and with children, but they are boistrous if allowed. They love rough play, the rougher the better, but tend to get over exited. Find a word you wish to use when playtime is over for you, any word will do as long as it is consistant, ie: calm, quiet etc, I use 'chill'.
I find gently placing the palm of my hands on their shoulder blades and then move one hand down to his chest and begin stroking gently has a calming effect and I use the word 'chill' at the same time, more often than not, they roll onto their backs to have tummy rubbed. after this I get up and walk away leaving the dog lying down. They either stay there or find somewhere more comfortable.

You dont say how old the children are, but if they are quite young and tend to scream in excitement this will only encourage rough play. The calmer the children, the calmer the dog :)

I must stress that when placing hands on shoulders, it is just placing, DO NOT PUSH, the dog will only push against you thinking this is part of the game, but you could also injure the dog.

All dogs have their little 'maddies' not just labs. They just go all out nuts for 10 minutes or so.

Kay

Sounds like what I call 'scuttle butts' to me - and at these times they don't always recognise the normal restrictions they've already learnt :(  I'd say manage the situation by keeping out of the way and enjoy him :)