A 2 GB card should net you about 600 photos, assuming you shoot at full resolution, or roughly 3.3 MB per image. Obviously, if you shoot any video, it will be less. A card marked Hi Speed writes information to the card faster. With your camera, it doesn't make a difference.
I am going on a trip to see several National Parks in September.
My Camera is a Canon PowerShot A710 6x optical zoom and has 7.1 Megapixels.
I have two questions:
Currently, I have three 2 GB cards and I wonder how many photos I will be able to store on them?
I noticed that two cards are marked Hi Speed, the other doesn't have this marking. What difference does this make?