iOS simulator and gps

From the Features > Location menu of the iOS Simulator, check the Location menu:

^{Note: The screenshot below is outdated, however the path above has been updated to reflect the proper menu location for this option.}

It provides you with several options pertaining to changing the location of the simulated device.

For those that are getting here in 2020, things have changed a little bit, You'll find the options to modify location settings under Features