The MMC cards are not new .... they are quite old.
They were before the SD card and were slow.
The SD card came along and the MMC card just about disappeared.
Within the last two years, there has been a resurgence in the MMC card, with it being used on some multimedia devices.
Speed has increased.
It is slightly thinner than the SD memory card and that can be a problem when used in some cameras.
The high speed SanDisk SD cards (Ultra and Extreem) already have more speed than your cameras can use.
On DSLR cameras, faster memory cards can increase the picture taking rate when the camera is used in burst or continuous mode.
DSLR cameras have more high speed buffer memory.
I own 3 digital cameras: Canon Powershot G2; Canon Powershot A720 IS; Konica/Minolta DiMage Z6. For the A720 and the Z6 I have been using the SD cards; for the G2 I have been using CompactFlash cards.
The specs for the A720 and the Z6 indicate I can also use MMC cards.
I note that new cards have come out that are "faster" and I could use that extra speed during picture taking sessions. Can I just buy and use these faster cards, or does each camera have limits?
Thank you for your time and effort in helping me with this.