We have some khaki campbells and will be getting chickens and were planning on adding a few (3-4) geese as well, primarily for grass control since we wont have any other grazing stock for a while, although their alarm function was another bonus. We plan to let the geese free range our land in the day and be penned at night. We can easily keep them out of the garden where children play, but I'm a little nervous about small children and geese anyway. Perhaps muscovy ducks would be a better alternative than geese, as they are also grazers? Although without the alarm function. What does everyone thing? Muscovies seem to be incredibly popular on this forum - much more so than in real life where I live, I don't know anyone who keeps them here, and I wonder why.
Most of the geese I had anything to do with as a youngster were rather nasty pieces of work, and nearly put me off geese entirely. I've had a few since then and they've been really good around people, even children. They can be a bit nasty to other poultry though.
We also have a load of Muscovies. I first encountered them in Wales, so they do have them there. My neighbour was forever singing their praises and now I have my own I fully agree with her. The males are a bit dumb (I'm sure their brains leak out through their skulls to make the wattles) and they have sharp claws so you have to be careful if you try to pick them up. But they are good grazers, good bug-catchers, the females make really sweet singing noises, and they are pretty tame - ours let you pick them up. When we have children visiting us, they get picked and thrown into the pond, which both the children and the ducks seem to thoroughly enjoy.
Here - have some gratuitously cute photos of my son playing with them...