Over 300k checkins for Foursquare, now how do I find you?

With the sheer volume of people that everyone is becoming connected to in  Foursquare, Brightkite, Latitude and Gowalla, I discovered something about the whole process.  Even with so many friends an no issues checking multiple services, there is no fast way to perform this task on any of them.

I have no groupings, easy search or other feature for locating just the user I want.  Not everyone broadcasts or has a widget.  Not everyone uses the same service so interoperability is non-existent.

So how do I best query where you might be?  What if you check in when you leave somewhere for privacy?  I am now at a loss to whittle through what are considered close friends, social friends and just followers.  As well as what service any one person might be on.  Could this be the birth of a winner or the death of many of the services?

How well does it really work for conferences like SXSW or Lotusphere back in January?  Everyone is very fluid during the day, moving at a constant pace.  By the time you check in and I check for you, you have moved and checked in again.  Latitude gets the closest in providing accurate and real-time updating as compared to the others.

Where is the value in this form of activity?  Is it in my ability to trace my own movements?  How long should I plan on being at a location before I get the urge to check in?  is there a rule on being in place?  Is there a rule on time before moving?

How do we bridge the location services into something more than an advertising platform for restaurants, bars and vendors to a service we need as people?  Is utilizing the service about a discount or socializing and locating?