OK, here is another way to enable both swap partitions, this way the faster microSD partition has the higher priority - only using the internal swap when it becomes full.

I've only started messing around with this Linux stuff, so if I'm wrong your comments are welcome. However it really seemed to have worked for me, I had setup a solitary swap of about 350MB and started to get sporadic low memory warnings (but conky did not show any problems), especially when using firefox with a bunch of other apps opened at the same time. After doing this I cannot recreate the memory warnings no matter how hard I try

Simply this:
Checking
From the above you can see the swap on the microSD is higher priority than the one on the internal, and so should in theory be used consecutively when the partition on the removable card becomes full.