Thanks CR. That makes a lot of sense for a Reader to be able to do.
Sony only recently made its devices available here in Australia, but none of them are manufactured here. Since the disaster(s) in Japan they've been out of stock and, as far as I'm aware, Sony hasn't put a date on when they might be back.
Most of the other brands aren't available here at all. Borders has just gone out of business completely in Australia, so that puts paid to it and its Kobos. And I haven't really seriously considered a Kindle because all of my books are in ePub format (and although I'm definitely not anti-Amazon, I do have a bit of an ideological issue with its level of control over Kindle users).
It's sounding like Sony might be the way to go, if I can source it locally.