I had two TCS3414 color-light sensors that I wanted to compare (The FN and CS packages, which have different filters). The I2C address is hardwired. After looking at how I2C works in terms of the SCL(clock) and SDA(data) lines, it seemed that turning off the SDA line would prevent the chip from getting a start or stop bit and thus leave it dormant. So used a CMOS analog switch (4066B) to switch on or off the SDA line to each device. This worked just fine for switching between the two devices. I know it's a hack, and the PCA9548 I2C bus expander would be a much better and technically correct solution, but I didn't have one handy.