sgarciav:
Maybe everyone just uses the trick with the AD0 line.
This sure seems like a straightforward method of reading from multiple sensors to me. As has been suggested, you want to make sure you don't have too many pull-up resistors in parallel.
How many sensors do you want to use? If it's less than 8, you could use a 3 to 8 decode chip ($1) to set one pin high (or low, I'm not sure which) at a time. Another option would be use use a '595 shift register (also $1) to set the AD0 line high or low. you could chain '595 chips to control lots of AD0 pins with three I/O pins on the Arduino.