That wikipedia entry was very informative, Jon, thanks. It seems to indicate that anything larger than a 1gb card might not work in my camera. It hints that those nonstandard 2gb-4gb cards might work in some devices, but doesn't go as far as linking to a compatibility list.

I wonder where I could look to discover if my camera supports either the 2gb or 4gb SD cards. A 4gb card in my camera would be a wonderful thing, if it could work.