Agreed. Phone locator is available with the free version of Lookout and works very well in my experience. Just a few weeks ago my wife came home and realized she didn't have her phone with her. Wasn't sure if she left it at work or put it down when she was in the grocery store earlier.
Went to Lookout's website and within seconds her phone was located in her office. In addition to this real-world example, I have tested the service several times and it never failed to correctly locate my phone or my wife's.
Frankly, this is the only reason I have Lookout installed. I have disabled all the other functions because I don't find them necessary.