This is the memory card used in 66 and N series Nokia phones. A 512mb were going for around £30 earlier this year. Very cheap if you are ordering something else - I bought a few other things so the postage wasn't as bad.
Designed as a result of the increasing demand for miniaturised technological supports, the MMC Mobile was specifically designed for the new generation of mobile phones. Though it is the same size as the RS-MMC, the MMC Mobile is distinguished by its technical performance (reduced energy consumption, increased operating speed).