USB Modem allows you to use Treo 600, Treo 650, Treo 680, Treo 700p, Treo 755p and Centro smartphones as a USB modem for connecting a desktop or notebook computer to Internet. To surf the Internet from your PC you will need only a USB cable and a Treo with GPRS/EDGE service or CDMA 1x/EvDO data plan. However, for more reliable work with Sprint or Verizon carriers you may need to purchase their tethering plan. Support for Windows Vista, Windows XP, Windows 2000, Mac OS X, and Linux operating systems; support for USB and Bluetooth connectivity; support for background mode so it is possible to make outgoing voice calls or perform other activity on the Treo without disabling the modem mode; support for Fax modem operation; small memory footprint (30KB). Version 1.59 adds Treo 755p and Palm Centro support.