I wound up with a SanDisk 128MB Memory Stick Pro Duo and the adaptor to make it fit non-Duo Memory Stick slots. Alas, my Clié cannot use Memory Stick Pro, only a regular (non-Pro) Memory Stick.
I don't suppose any of y'all have a Memory Stick Pro compatible device, and a regular 128MB Memory Stick that you'd like to upgrade to Memory Stick Pro (uh, I'm guessing that's an upgrade but I'm a little fuzzy on the difference) that you'd like to swap? Even a 64MB Memory Stick would be useful to me; certainly more useful than this Memory Stick Pro that I can't use at all. (Actually, I guess it doesn't matter whether you have a suitable device; I just couldn't imagine having a Memory Stick and wanting to take the trouble to upgrade it unless you have something to use it in. But I really shouldn't impose the limitations of my imagination on others, especially when I'm asking for a favour.)
I've been feeling a little squeezed with the one 128MB stick I've got, so I'm hoping to move the thrice-weekly automated backups and previous-months checkbook/sleep-log/fuel-economy spreadsheets to their own stick, and maybe eventually obtain a third stick to keep a library of e-books on.
(It's too bad the camera and the Clié don't use the same type of memory. I wonder whether ∃ a Memory Stick Duo -> Compact Flash (Type I) adaptor. Not that that would solve my PDA space problem though.)