I therefore assumed that checking one or more of the "Disk Sharing" check boxes on the front end connection details screen for rDesktop would work the same way ... but I just tried it & it didn't - checing myDocs and/or Mem Card's seemed to have no effect on the target PC. Not sure if that's a bug or if I'm just misunderstanding the purpose of those check boxes. I'd be interested to know the answer either way ...
nb - Only contemplate this method (even if it works) if you trust the target system to be secure and virus free; it potentially exposes your n900 security-wise.