GA dept are always helpful and full of very useful knowledge, they often know the sites we are asking about because they have dealt with them before and are able to pass on quite useful tips ("there's a lively noise complainer in that house 500m away" was one)
Our FOI is a man of great common sense and knowledge, he's done the job and knows all the wrinkles, so although I can't pull any wool over his eyes he often advises on the best way to achieve things, I've known him ten years and our standard, very rude greetings to one another have been known to cause white faces and trembling in the ops dept.