Halifax/Bank of Scotland do Electron with their easycash account (very basic account), i've had the account over a year and put £20 in it in Dec 2007 solely for FR journies so it will prob be a while before I top it up.
Abbey definately do them and I think someone said the CO-OP do as well.
You can apply for the Halifax one online so you wouldn't even need to visit a branch until you needed to put cash in