digital memory

[DanL]

Size of card you select depends on the type of media you use(Compact Flash, memory stick, etc), the camera megapixels (2,3, 5, 8?), the resolution you shoot (jpeg low, jpeg high, TIFF, or raw), and where you plan to shoot (locally where you can download after a dive, or a week long vacation where you don't plan to download your cards)
I have a 3 and 5 megapixel camera, and usually shoot high res jpeg. I use Compact Flash cards. Started with 125MB on the 3MP camera and that was fine - could get 45 pics on one card. But that was too small for the 5MP camera underwater. I now use a 512MB card on the 5MP camera when shooting underwater because I can get about 110 pics before changing out the card.
As for speed - for Comp Flash cards it's not related to size. Maybe so for other cards, but for CF you can buy cards of different write speeds - from 2x to 12x, I think. But for my camera, an Oly C-5050, I think the max write speed it can use is only 4X, so paying a premium for a really fast card isn't necessary.
For more info, and probably more accurate than my memory, search this site - a LOT of great digital photog info:
I have about 6 cards now - 128's, some 250's and a 512. I fill em all up when on vacation. Watch the prices at - the prices should start to fall dramatically since the major manufacturers have announced wholesale price cuts to about half the recent prices. I just bought a 512MB card with rebate for $59 and prices should come down even further from there soon.
Have fun...
Dan