I moved to a house with a meter and made a big saving on my water bill. I used to pay �40 per month, and now I am on a meter, the bill is �10 per month!
I have always been careful with water usage anyway - not leaving taps running and having a shower instead of a bath - that sort of thing. But the saving still surprised me. I have a water butt, and use this water for the garden, and also for flushing the loo - it doesn't save much cost-wise, as water is cheap per cubic metre, but I like to feel I am not wasting water!
It's definitely worth looking into.