A photographer suggested I try the Lexar Pro dual slot flash card USB2 reader. The SD slot on the new 13" MacBook Air is of no use to me because I use a Nikon D200 camera that uses CompactFlash cards. I'm getting 36MB/s READ speed with the Lexar Pro which is good but not great. (The SanDisk Extreme IV FW800 reader can import the same memory card at 65MB/s.) However if you are reading in your images from an SDHC memory card, you are better off using the SD slot (28MB/s READ) instead of the Lexar reader (18MB/s). Some on this forum propose using an SD card for backing up the MacBook Air. Write speed is a different story. Backing up to an SD card is slower (22MB/s) with the SD slot. The dual slot reader is slower at 16MB/s. Backing up to a CompactFlash card is better at 35MB/s. A notebook HDD in a USB enclosure can write even faster (37MB/s). An SSD in a USB enclosure can't go any faster due to the limits of USB 2.0. The Notebook HDD in an enclosure has the best price/performance ratio. For example, a 128GB flash drive like the Patriot Export Magnum will cost you $260 on Amazon. A 120GB SSD + enclosure will cost you $275 on MacSales.com. A 500GB HDD + enclosure will cost you $80 on MacSales.com.