The diffference between SmartMedia and CompactFlash:
They are basicly the same except the memory controler chip is on the compact flash memory so that when the camera reads the card it just reads from the controler chip that reads from the memory. That means that you can have a 256mb compact flash card with any camera, but with Smart Media its different. Smart media contains just the flash memory and nothing else, so the camera itself has the controler chip, and if the controler chip cant handle more than 128mb SM card then a 256mb SM card wont work. The only way for a SM camera to read a higher capacity memory than its intended for is a flash upgrade. I think most cameras now have the option to just download the upgrade and do it yourself but most manufacturer offer a service that involves you sending them the camera, they upgrading it and then sending it back. Compact flash is more expensive than SmartMedia but on the other hand it offers more memory and more "support", also it is in a caseing so that it wont get scratched. Smartmedia is cheaper and is very very thin and it can take scratches.
I have a Olympus3030z camera that takes only Smart Media flash memory and it doesnt bother me at all. I have one 32mb card that came with the camera and then one 64mb card, which alowes me to take about 150 pictures in
this quality.
One of the problems with digital cameras today is the write speed, if I choose much higher resolution than I normaly have it takes a while for the camera to write to the memory, so higher resolution is pointless most of the time.
Personaly, if you are thinking about buying a digital camera, think first of the quality of the camera itself and the price, the memory medium is not that important.