Did I tell you about the time that I shot an elephant in my pajamas?
I think Rob Galbraith's site suffers from too much information with not enough conclusions. The data could use to be mined a little more. What I'd like to see is...
Cards speeds tested with one particular reader (for maximum, consistent, and comparable performance)
And
maybe one particular card tested with various digicams.
If we know the max read/write speed of our camera, we can then see at what point the extra speed won't help when shooting. Of course, it doesn't help that it hasn't been updated in 11 months, but I am not in a position to criticize anyone for slow web site updates.
LMarge, yes, write speed is what you're interested in - that's the measure of how quickly pictures can be written to your camera. It looks like the S2 writes at about 3m/sec - so I think that most any high-speed card will be more than fast enough to capture as fast as the camera can write.
I don't have too much in the way of specific brand recommendation. I believe the memory in the cards themselves is usually made by a relatively small number of vendors, and that's probably the most likely point of failure, so in many ways, I think one card will be as good as another... but I admit that we're venturing away from known fact and into hypothesis.
One of my main concerns is that you get a lifetime warranty, which I think most offer.