One of the coolest features of the iPhone is how it can customize certain information and services based on where you are, for example in Guidance on the iPhone you can ask it to find your current location and display the prayer times for that location instead of having to search for the location as you currently have to on Guidance for the Mac.
When Apple introduced Snow Leopard in 2009 one of the features they included in it was the same functions you call on the iPhone to determine the user's location. And they even updated some of their applications to make use of this, such as the time zone selector in the Date and Time preference panel
Of course this is not going to be as accurate as the iPhone is, the iPhone can use a GPS or cell tower triangulation to find your location. What Snow Leopard (and the iPod Touch) use to find your location are the names of the different WiFi hotspots it can see. So while not accurate enough to give you turn by turn driving directions, it is definitely accurate enough to set your time zone and hopefully accurate enough to automatically set your prayer time location, this would be especially useful for people with laptops who travel frequently. InshAllah I plan on looking into utilizing this feature in an update for Guidance on the Mac (which does still have ongoing development). So definitely keep an eye out for a Guidance update soon inshAllah.