Someone, somewhere on the Internet claimed recently that the hama USB 2.0 Card Reader 9in1 doesn’t work with OpenBSD 3.6. This is not true, the system detects the card reader and the flash cards you plug into the reader.
There is a problem with the un-plugging procedure. The system does not detect the removal of the card from the reader and won’t recognize the card when you put it back into the reader. I’m not sure why it happens, because the system does detect the insertion and removal of my Actina 128MB Flash memory stick (plugged straight into the computer, not via the card reader).
The cure is childlishly simple: disconnect the card reader from the compute before you remove the card from the reader. Then, remove the card from the reader and connect the card reader to the computer. It’s a stupid trick, but it works on OpenBSD 3.6. It may work with other systems and with other Flash card readers.