I'm about to buy a 2GB MMCmobile memory card for my 770, but should I consider camera compatibility first? Considering form factor and the formatting, are any, some, or all MMCs co-compatible with my Canon A520 (it came with MMC and now I use SD)?

Here's my thinking: When camera phones came out the breakthrough wasn't so much the quality but the ability to immediately "send" the picture off. Think hardware for the poor man's war correspondent, say. Now apply the same concept to somebody out in the field without a computer, but with the 770 and the Canon...

• take a photo
• remove the memory
• insert it in the 770
• upload it to a live blog, etc.

Who's tested that?
How did it go?
Should I buy a standard RS-MMC instead of a MMCmobile?

Thanks.

I've used an MMC card in a canon a520 (the card it came with it iirc), so an rs-mmc would probably work in it (using the extension thingy). I never tried though.

I have tried just to see since I have a bunch of cards.
Both RS-MMC & MMCmobile work on my 770 & my Panasonic FX7 digicam.
However, MMC is slower than SD in my camera; it affects write speeds (helpful in burst mode).
Canon's website should have a memory card compatibility FAQ or some sort to help you learn more about your camera.

This is a cool idea. I was thinking about the same thing.
But will the system files be affected when the card is in the digital camera and photoes being written into the MMC card?

System files are not affected... at least with my FX7.
It just added its own folders and files.

Success...

770 with 64MB swap file to
Kingstone 2GB MMCmobile to
Canon A520
...and back to 770.