Jaye we have two hens (hoping to add to our little flock this year though
) in a run in our back garden and have neighbours on both sides and no one has complained.
People have commented on how nice it is to see hens in the garden as not many people seem to keep them round here anymore.
Ours do sometimes make a little noise if something spooks them, or if one goes into their house to lay an egg and the other's left out on her own (it's like they have a little conversation going); but I would agree with what everyone else has said - they are no more noisy/smelly etc than most other pets.
If you're renting you might want to check that it's ok for you to keep poultry, I know some places don't allow poultry to be kept in gardens (Henry has this problem in Milton Keynes).