Can a SanDisk Ultra 4GB CF card be used with my PowerShot S200 ELPH?
There is no mention of capacity limitations for your camera so I'd say yes. I did the same with an old G5 I have and put a 16GB CF card in it and it worked.
Indeed, the Sandisk Ultra does work. It's time for a mea culpa---my son had to remind me that CF drives must be formatted before use!
lol ! your welcome!