Tapwater.org

[Firestorm]

I just found this website, if you give it a location it will list places nearby where you can refill a water bottle for free with tap water (I'm not sure if you have to use one of their own bottles but I cant see why you would) - Places like pubs/shops that have signed up to be refilling stations.

Its not great for rural places (yet) but there seems to be loads of places in London

http://www.tapwater.org/refilling-stations

[Risker]

It's a great idea, all too often I've found myself having to spend £1.50 on a bottle of water which really is quite absurd.

I can't really see myself using though somehow.