The rz1715 - Their low-end Mobile Media Companion, the rz1715 only has a 203MHz processor, 32MB of RAM, a 3.5-inch LCD screen, an SD expansion card slot, but no WiFi or Bluetooth.
It's no secret that Bluetooth devices that are in discoverable mode are... well, discoverable, so we figure it was just a matter of time before an independent organization set up a massive network of transceivers to track their every move.