Last year, MIC Gadget started selling a card reader for the iPad that could take both CF and SD cards — an accessory they’ve now upgraded to the All-in-one Card Reader for iPad. There’s a big review of it over here, but the short version is that for $32.90, you get an accessory that can pull images and data from CF, SD and microSD cards as well as USB onto your iPad.
Once you get into the technical details, this accessory actually has a few other cool tricks up its sleeves, too. For when the reader needs more power than the iPad can put out — say for a USB disk — you can use an external power source. The reader also has a bit more grunt behind it, so can handle 600X CF Cards and Class 10 / UHS-I SD Cards. It’s cheaper and more versatile than Apple’s version — but you can bet it isn’t constructed nearly as robustly.