I thought we could compile a list of confirmed to work SD cards, since the Sheevaplug is pretty picky with them. Preferably model, brand and where it can be found.
It seems Sandisk would be a fairly safe bet to go with.
I've tried both a micro and a regular 2GB Sandisk card. And neither works. Not with the latest kernel nor the one built in, it always says mmc0: error -110 whilst initialising SD card.