Iphone MapKit displaying route

I would like to show the route between 2 locations, from the users current location to a certain point on the map. I have seen this done in a couple of applications like layar. http://itunes.apple.com/us/app/laya开发者_StackOverflow中文版r-reality-browser/id334404207

Can someone give me pointers on how to achieve this on iphone sdk 4

Thanks

Try using kishikawakatsumi's code on github.

Looks like he provides a wrapper around the Google Maps routing API which will give you the route, and then some custom MKAnnotations to handle drawing those routes in MapKit.