Memory Card

Thee are currently four types of cards found on digital cameras.
Compact Flash, SD, xD, and Sony memory sticks.

Currently the SD card is used in more cameras.

It is all about money.
Capitalism at work.

The xD memory card was developed jointly by Fujifilm and Olympus.
The Sony memory stick was developed by Sony.

These companies derive some money from each memory card sold.

No company derives money from the sale of compact flash and SD memory cards, except the manufacturer of the card.

The compact flash and SD memory cards tend to be less expensive.

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There is no point in limiting your camera choices over type of memory card. They are all relatively inexpensive these days.
Just get the camera you want.

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namely capacity and physical size
CF is larger sized, have higher max capacities, and tend to be cheaper due to the fact that it's easier to not have to shrink the components down to XD, SD, and MS sizes. Doing a more or less same size price comparisons between all those formats, CF will be cheapest, ranging from a 'lil bit to "significant, but not enough to be THAT cost prohibitive". SD currently maxes out at 4GB (6 or 8GB almost/alr upon us) while CF curr maxes out at 16GB (24 or 32GB alm/alr upon us?). Keep in mind the near max capacities of both SD and CF are at premium prices. A 16GB CF card goes for around $1,100!

I personally like SD. It's small postage size means I can put several of them in my wallet comfortably which is quite convenient. My PDA is small enough to unable to have utilized a CF slot. Ergo, I ended up buying 2 diff types of SD card readers. My handheld GPS device is about as small as my PDAs, so a CF slot may have worked, it would've been a stretch. My old Nikon Coolpix 880 uses CF, but that was a hand-me-down digicam, so I simply used CF b/c I was stuck with it. My new digicam is a compact, advanced P&S, so a CF slot would've been difficult to pull off in lieu of SD card slot. While I am firmly rooted in SD, I do like using it, so it works out well.