Kingston Ultimate 133x card tested using the procedure outlined on Dyxum, where you count the time the card is being written to. 13.47 seconds for 9 RAW photos. That is 1.5 seconds per RAW photo, where the average file size was 8.51MB, for a throughput of 5.69 MB/sec.
In the A100, this means you can take 9 shots quickly in continuous mode, which then bogs down to a slower frame rate as the buffer stays full. That's pretty good performance. If you use JPEG, you can shoot continuously, about 3 frames per second, until you fill the card.
Using Fine JPEG and manual focus, I took 13 photos in 4.03 seconds (but not counting the time to flush the buffer -- I'm not looking for a memory speed, but just frames per second). Thats 3.2 frames per second! That's with DRO+ processing turned on. However, the average file size was 3.54MB (due to photographing a lot of the same color), so with most photos, the files would be larger, and the frame rate probably a bit less. Still, impressive. Unlike with RAW, there doesn't seem to be a limit where it will bog down -- it kept going.
With AF, I took 17 photos in 6.75 sec., which is only 2.5 fps. Noticeably slower, but still good. In lower light, with AF, it seemed to bog down when it felt a need to recheck focus, taking as long as 1fps at times. Given the performance in MF mode, I think this overhead is entirely due to AF.
My older 50x card would bog down after only a few shots.
The verdict? The Alpha A100 can take advantage of faster memory cards.
When set to Auto ISO, the Alpha A100 usually will choose between 100 and 400, depending on conditions, with firmware 1.04. In Sport scene mode, it will choose ISO 800 if it is dark enough. (With firmware 1.02, it may also choose 800 with Auto ISO, but I am not sure about that.)
In Auto or modes where the A100 chooses the aperture, it will not automatically select less than f2.0, even if you have an f1.7 lens attached.
Tip: if you need to swap back and forth between two groups of settings quickly, such as different white balance settings, consider turning the dial between Auto and one of the more manual modes. In other words, use P mode with white balance set to tungsten for use indoors without a flash, but to use flash, turn it to Auto mode when you pull up the flash. This is faster than going into the WB menu, which takes many key presses to back out of the tungsten setting.
Build-your-own pop-up flash diffuser:
After following what Al had done, I created a larger variant of this design. With the larger one, I could tell that the harsh flash shadows, while still present, were softened (not as sharply defined). The effect was most notable when photographing macro. It certainly isn't a cure-all, but if you want your flash to be a bit less harsh, it's worth a try. NOTE: do not let any substance touch or get too close to the flash unit itself; it gets very hot (for a short amount of time) and can ignite materials unexpectedly. Besides, the effect is better the further away the diffuser is from the flash.
To stop the camera from focusing while it is resting on your chest (because of the "eye-start focus" being triggered), certain mode buttons can be pressed, such as Drive or AE +/-, when lowering your camera. When you are ready to shoot, a half-press of the shutter will cancel the mode.