I've heard lots of different things about this too and we offered a little bit to Jacob every now and then from fairly early on. We didn't boil the water for 5 minutes either - it was just cooled boiled water from the fridge. Through trial and error though we worked out that he preferred it cold from the fridge as opposed to room temperature.

The water seemed to help him a little bit if he was a little unsettled (and we knew he wasn't hungry etc as he'd been fed and had all he would take from a bottle).

It took him a while to like water, but he happily drinks it now!