I bought £250 worth of bitcoins on Sunday through https://localbitcoins.com. From memory I got 0.4675 bitcoins. I paid by bank transfer, it took around an hour.

What do you mean by real time transactions? If you're exchanging bitcoins for other electronic coins, you can use an exchange like bter.com or cryptsy.com and its instantaneous.

But yeah, if you want to exchange for cash its an illiquid market and it takes around an hour. Try:
https://localbitcoins.com
https://bitbargain.co.uk
https://quickbitcoin.co.uk
https://bittylicious.com/‎

https://localbitcoins.com has the option of meeting a seller in person to do the transaction.