I work for Orange retail and only noticed how cheap the Sandisk 512mb M2 cards are instore. Only £9.99!!!
Although you can pick up a 1gb online for as little as £16-£17, some people like myself tend to buy the bigger cards for no reason as i only use my k800 for photos so a 512mb will do me nicely.
As an added sweetner i get 20% staff discount so it is only costin me about £7.99...bargain! :)