http://www.nikonchat.com/nikon-s630-memory-card/

What memory card should I buy for a Nikon S630?
What memory card would be best for him? He says he will take either SD or SDHC memory cards. Should I get a Sandisk card should I get regular or one of the Extreme Ultra II or III for that?
High Speed "extreme" cards really only makes sense if you are using a high speed card reader to transfer images to your computer. If not, buy the larger, Cheap SD (HD) card you can find. The Nikon S630 can not write to the card in "extreme" speeds, you can not read from the card at high speeds when connected directly to the computer with a USB cable, cards, way cheaper are not slow, and in all other respects, they behave exactly the same as the more expensive.