The answer is... truckloads. However, bear in mind that Australian trucks are smaller than those used overseas.
Nintendo announced today that 30,000 DSi units were sold in the 10 days from launch on April 2. The press release makes no mention of how these figures compare to other hardware launches. But we do know that the DSi beat the PSP's launch sales of 27,000. Not bad for a hardware revision rather than a genuinely new device.
Nintendo still holds the current record for launch sales, shifting 32,900 Wiis in just four days back in December '06.
We asked Nintendo to provide comparative figures for the first 10 days of the original DS and DS Lite sales, but they have yet to respond.