Also note that if the US flag is displayed with flags of other nations, all of the national flags must be displayed at the same height. The flag of the home country will usually be the rightmost flag, ie if you are in Japan, the Japanese flag would be displayed in the rightmost spot. Displaying the flags of other nations is some what simpler because unlike the US flag, most other flags are symetrical.
Also, flying the US flag upside down is a disress symbol, if you fly the US flag upside down, you must fly all other flags upside down as well. It is not disrespectful to fly the US flag upside down, but it may be considered so with other national flags.