If you’ve ever tried to use your cell phone to locate a friend in a crowd, you know that it can be like finding the proverbial needle in a haystack.  Now there’s a free new iPhone app named Marco that provides real-time graphic updates on the location of 2 people.  You can share your location with any phone that’s equipped with a browser, so both people don’t need to have an iPhone.  You can find Marco in the Apple App Store under the name “Marco Friend Locator.”