For anyone who wants to save and hasn't seen the Moneysaving Expert site, it is a must. We've saved £lots with it over the years. This article is a particularly useful, long list of possible ways to save and includes motivators for not spending.
In these days of high petrol prices, it can be useful to know where the lowest local prices might be. The petrol prices site gives the lowest prices around and will send a weekly e-mail with the cheapest local filling stations. This probably isn't useful in the depths of the country but is of value in the city and interestingly, the cheapest stations vary.
e-on, the energy company has an "energy-fit" site. Some friends of ours are one of the featured families.