First off the USB cable for the Sanyo 8100 is the same as for the Sanyo 5300.

Once you have the USB cable you can hook up the sprint vision phone to your computer and use it as a modem.

All you need is to download the Free Sprint PCS Connection Manager Software. (click the link and choose software download site from the middle of the page. And then select Windows 98se, ME, 2000, XP from the platform dropdown, and then choose (Vision) PCS Connection Manager Software for USB Cables and Airprime PC 3200 Ver. 01.01.022)

Be aware, this package is a 77MB!! download. I dont know why but it is. When you install it make sure you choose Sanyo from the list of supported devices.

After installation you are ready to go, just launch the PCS Connection manager with the phone connected via USB and you are online. I got connection speeds that are comparable with a 56kbit Modem.

Camera Phone Buyer's Guide
More Vision and Sanyo 8100 How-Tos


Screen Shot of PCS Connection Manager: