Compact Flash versus Microdrives
While it goes without saying that digital cameras don't use film, this does bring up the question of what one should use to store images, compact flash or microdrives. The interface to both is based on the PC Card (PCMCIA) standard and both have the same form factor so that either can be used in most digital cameras (those that use Sony memory sticks and other less common media being the exception). On the inside, however, they couldn't be more different.
CF Cards contain flash memory that will retain the information even when power is removed. They have no moving parts whatsoever and are extremely reliable and durable. Though not indestructible, they have been known to survive going through the washing machine in pants pockets as well as being run over by a car on a muddy road. Although the cost of memory continues to fall, CF cards tend to be more expensive than microdrives on a per megabyte basis yet may be expected to last longer.
Microdrives are literally small spinning hard drives the size of a dime inside a case the size of a CF card. As such, they are more susceptible to damage if dropped or otherwise roughly treated. Originally developed by IBM, they are now marketed by several other companies as well. Capacities for microdrives have tended to be greater than for CF cards, although Lexar has recently announced CF capacities up to 4 GB making this difference less clear. Speed for microdrives is often not as fast as for CF cards either, since the process involves mechanical parts and the inherent seek time of a hard disk.
For outdoor work, you are almost certainly better off with CF cards if for no other reason than their increased reliability. There would be nothing worse than to have your prized images lost when your drive fails.
Rob Galraith's site contains lots of useful information on compact flash and microdrives including performance test results. Before buying storage media for your new digital camera, you owe it to yourself to read it thoroughly.