OK, so I bought a bigger micro SD card, and decided to clone my existing microSD card onto it.
I used dd if=/dev/mmcb1k0 of=/dev/uba bs=4096 conv=notrunc,noerror (/dev/uba being the microSD card reader I have plugged into the USB port).
This being finished, I used fdsik to delete the second partition on /dev/uba, and recreated it to be as large as the remaining space on my (16 GB) microSD card.
I then ran resize2fs /dev/uba2 to complete the job.
Regardless, upon booting onto my newly cloned drive and running df -h, the drive appears as under 2 GB (and completely full).
I imagine this is because of how booting/mounting from the SD card is handled, but I don't really understand what's going on at this point.
What do I have to do to make this partition appear the proper size (>15 GB)? I basically can't do anything with the microSD card I bought with the OLinuXino, because it's entirely full for all intents and purposes (came that way, annoyingly).
OK, for some reason resize2fs only works in this circumstance where the partition is mounted.
Tried it again while mounted and it did the "on-line resize" thing. That time it took.
:)