What location-based apps pinpoint friends on iPhone/Web interface?

[a1insun]

Hi,
Are location-based apps that allow you to be sociable (share your location with other friends who use the app) typically only something where you can see your friends' locations on the physical iPhone you are holding in your hand? Or are most apps like Google Latitude where you can also look up where your friends are online? The reason I ask is I am getting together the plans for a business, and need some research done as to which iPhone apps are conducive to tracking the location of friends (customers in our case) via a website.

In fact I would be willing to pay money for the research to be accomplished. Let me know if want a part-time, temp job of making some screen shots and giving some advantages of various location-based iPhone apps. I'm quite serious about that, and I hire through o-desk.com.

The unique thing I want to do is have a call center set up (sort of like OnStar for everyone) that can access the location of customers by looking up where they are at any time in any app. But sadly the call center I'm looking to probably use will not allow iPhones to physically be in the center for privacy reasons. So I'm trying to find a creative work around (like to find apps that give a web interface). I know Google Latitude is good like this. Any other ideas?

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