The USB-I2C module is a low cost USB to I2C module, with a simple command set, and interfacing to any I2C device.

The USB-I2C module provides a complete interface between your PC and the I2C bus. The module is self powered from the USB cable and can supply up to 70mA at 5v for external circuitry from a standard 100mA USB port.
I2C Devices - Any registered or unregistered I2C device. Host support - Drivers available for Windows XP64, XP, 2000, ME, 98, CE.NET V4.2, Linux, Mac OS8, OS9, OSX.
Voltage - Self powered - 5v available
Current - Up to 70mA available for your own circuits
On-board Pull-up resistors - 4.7k
Digital I/O - 1 Input and 2 I/O available when not using I2C.
Analogue Input - 2 10-bit channels available when not using I2C.