Thanks qole and meizirkki for the tips. Unfortunately the tar command didn't work either; really strange. I did end up just extracting on my Windows box and copying over to my card, and now Mer starts up!

Am I correct in understanding that there are no applications installed in mer except for the few like a terminal, tear, and leafpad? (I thought OO and Firefox were included, for some reason.) Any way to get my maemo installed apps to show up?