Q I am thinking of buying a Canon S5IS camera that uses SD memory cards. However I am told that I need a "card reader" My computer has lots of free 2.0 USB slots, but I don't know what reader is compatible with Linux. (I'm running OpenSUSE 10.3.)
A A far more difficult question to answer would be "which card readers do not work with Linux?". Some people have reported problems with the 99-in-one type card readers. This is usually caused by them running a home-built kernel stripped of all the superfluous options. These devices often need the SCSI_MULTI_LUN option enabled, which will be the case with any default distro kernel, because each card port on the reader is seen as a separate device. If you only want to use it with one type of card, the single-format readers that look like a USB pen drive are more convenient; you just plug the card into the slot and the reader directly into the USB port.
You may not need a card reader; Gphoto2 is able to download pictures from most cameras via their USB cable. Your camera is not in their list of supported devices, but if it is a newish camera, this should change soon. If you use KDE, type camera:/ in the Konqueror location bar to see a list of connected cameras and the photos on them. Having said that, I find a card reader faster and more convenient, especially as it means I can put a card in my laptop and carry on shooting with another.