Update as promised on racingtowin:
Started 1 Feb on 30 day free trial, continued on paying basis (weekly) 1 March.
I started backing and laying 1 March but quickly decided to opt for back only using 3m method.
Betting bank started with £1250 now stands at £3740. I have not backed consistently as I was away for almost 10 days.
I am NOT plugging this outfit as I am very sceptical of tips services, more so than many but this one seems to be getting it right so far. Saturday and Sunday showed 6 successes from 11, I did not back as the weekend is for relaxing not working.

Regarding arbs, I have glanced at my old files and I remember why I gave it up:
The stakes required to give a reasonable return are very high. I also agree with Paul's comment that it is easy to miss the opportunities unless you are quick.
Some websites select the opportunities for you but it seems that the good ones have already gone when the site updates them. E.g. betbrain.com
Maybe the exchanges offer better returns. As of today theri best "surebet" is tennis and offers a return of 1.94%. Thats 20 quid on a grand!
Personally I am looking for a much better return.