"Green House Corporation will release the "GH-SDCM512M," a miniSD card with the highest capacity, in the back part of July. It is Open Price, but indicators suggest it should cost around 38,800 yen. The GH-SDCM512M is the first miniSD card with a 512MB capacity, and it is intended for use in cellular phones for recording high resolution images and video. Green House has publicized a list of phones that are compatible with the cards - this includes the NTT DoCoMo N, F, and SH series, as well as au's A5407CA and A5505SA."
The mini SD card is available for just under $350 and is the first mini SD to come with a 512MB capacity, which has a transfer speed of 8MB/sec.