Alvin Hall gives some great money saving travel tips. Alvin mentions
http://www.bestvaluefares.co.uk/ which is brilliant for getting cheap train fares .
They have an excellent service on the site called "Cheapest fare finder"
How does it work? It shows the cheapest fares for all train operators on all routes. Select your preferred dates and times of travel to see the best value fare you can buy. By being flexible with dates and times and booking well in advance of your travel date you can often find cheaper fares.