Reading some of the past posts of Tube Diaries, I decided to jog along to the nearby station to check on my Oyster card usage. True enough, all my post 7pm travels are only charged at £2 (normally £2.50 or £2.80 on non-Oyster). Goody... I now stand to save a couple of quid a week.
Problem is tfl has been slow in advertising this fact. According to the TubeGeek, the tfl website contains the information buried somewhere although I couldn't find it. I did find something I did not know of - price capping. Here are the rates.