If you take a lot of digital pictures and would like to view those pictures on an iPad, you can buy the Apple iPad Camera Connection Kit. The kit includes two adapters that fit the iPad’s dock port, a Secure Digital Card adapter, and an USB adapter.
To read a SD card, you just plug it into the adapter and then plug it into the iPad’s dock port. The iPad recognizes the card and starts the Photos app, which you use to view the pictures and you can download them to the iPad. You use the USB adapter to plug a camera directly into iPad, which then starts Photos to display pictures or download them.
Most digital cameras today use SD cards, but some DLSR cameras use Compact Flash. A company called M.I.C. Store sells a CF Card Reader for the iPad. The reader supports cards up to 400X speeds, and it has a USB port to plug cameras into the iPad. The readers ships on April 25, but you can preorder it now for $29.90.