I'm trying to increase the ram on my old computer with a 2 GB sd card. You can configure Windows to use an SD card like RAM and I'm wondering if Ubuntu has that same ability.
If I am correct you need to format it as a swap partition:
Plug in the SD card.
If Ubuntu automounts the device, unmount the device.
sudo mkswap /dev/sda1(assuming /dev/sda1 is you SD card)
sudo swapon -p 32767 /dev/sda1(again assuming /dev/sda1 is you SD card)
and that should do the job
You can check this by typing
cat /proc/swaps into a terminal and you should see you device listed (/dev/sda1)