PCMCIA cards were first seen in aroud 1990. These cards were used to transfere data to PC's and other devices. Then in the early 1990s, a number of smaller memory card formats arrived, including SmartMedia, CompactFlash, and Miniature Card. Smaller cards for cell-phones, PDAs, and compact digital cameras drove a trend that left the previous generation of "compact" cards looking to big. In digital cameras SmartMedia and CompactFlash had been very successful, in 2001 SM alone captured 50% of the digital camera market and CF had a stranglehold on professional digital cameras. By 2005 however, SD/MMC had nearly taken over SmartMedia's spot, though not to the same level and with stiff competition coming from Memory Stick variants, as well as CompactFlash. In industrial and embedded fields, even the venerable PC card (PCMCIA) memory cards still manage to maintain a niche, while in mobile phones and PDAs, the memory card market was highly fragmented until 2010 when micro-SD came to dominate new high-end phones and tablet computers. Class 4 cards will be OK for taking pictures on a digital camera but if your camera will take Full HD video, then a class 10 card will be needed to receive and store the huge amount of data these cameras produce.
Flash drives are great for storing your pictures as they are very reliable and hold much more date than CD'c or DVD's. To download from your camera we would advise using a downloader pluged permanantly into you computer. This is a much safer way as pluging a very small cable into your camera can and does damage the very small socket that you plug into. In general stick to the names you know like, Fuji, Lexar, Sandisk, Kodak etc and avoid, those you don't recognise the name of.