Yeah, it depends on what u want to use it for. The findmyiphone app is primarily (as the title suggests) for finding your device in case it gets lost. Google Latitude is to track where your friends are located.

As far as I know, they both track your iPhone, only with Google Latitude you have to have the app installed, whereas FindMyiPhone also works without app (it’s installed in your MobileMe-settings).

Although I was a bit bummed that I couldn’t seem to install Find My Iphone on my 3GS, my brother told me I basically could just register for it on an iPad and still use the MobileMe service. Now Google Latitude has been released and to me it seems to have the same function. I don’t quite get what the differences are yet, maybe anyone of you can shed some light on this?