I feel like an idiot! Its mapview.setAnnotations not mapview.addAnnotation. I kept going over the code and wondering why only 1 location was being added. Below is the section of code for adding the points. Thanks for all the feedback.

mapview = Titanium.Map.createView({
        mapType: Titanium.Map.STANDARD_TYPE,
        animate:true,
        userLocation:true,
        region: {latitude:lat, longitude:lng,      
               latitudeDelta:0.01, longitudeDelta:0.01},
        regionFit:true
    });
    mapview.setAnnotations(points);
 
var points = [];
for (var c=0; c<data.length; c++) {
        points[c] = Titanium.Map.createAnnotation({
            latitude:data[c].lat,
            longitude:data[c].lng,
            title:data[c].title, 
            subtitle:data[c].subtitle, 
            pincolor:Titanium.Map.ANNOTATION_PURPLE,
            animate:true,
            myid:c
        });
    }

Joe - can you share the full code of your working example? I can't get mapview.addAnnotation to work in my for loop. I'd like to look at your code and see what I am doing wrong.

This works for me:

var win = null;
    var pin = [];
    win = Titanium.UI.createWindow({
        backButtonTitle:'Back',
        title:'Title',
        tabBarHidden:true
    });
    mapview = Titanium.Map.createView({
        mapType: Titanium.Map.STANDARD_TYPE,
        animate:true,
        userLocation:true,
        region: {latitude:lat, longitude:lng,      
               latitudeDelta:0.01, longitudeDelta:0.01},
        regionFit:true
    });
 
    for (var i=0; i<data.length; i++) {
        pin[i] = Titanium.Map.createAnnotation({
            latitude:data[i].lat,
            longitude:data[i].lng,
            title:data[i].title, 
            subtitle:data[i].subtitle, 
            pincolor:Titanium.Map.ANNOTATION_PURPLE,
            animate:true,
            myid:i 
        });
        mapview.addAnnotation(pin[i]);
    }   
 
    win.add(mapview);
    Titanium.UI.currentTab.open(win,{animated:true});

Got it working except its only displaying 1 location. The code is below, can anyone see what I'm doing wrong?

var lat = '';
var lon = '';
 
var url = 'http://localhost:8888/class-services/services/json';
 
var data = [];
 
var view = new Object;
view.method = 'views.get';
//view.hash = hash;
//view.domain_name = domain;
//view.domain_time_stamp = timestamp;
//view.nonce = nonce;
view.view_name = 'yardsales';
 
var xhr = Titanium.Network.createHTTPClient();
xhr.open("POST",url);
 
xhr.send({data: JSON.stringify(view)});
 
xhr.onload = function() {
 
  Ti.API.info(this.responseText);
 
  var data = JSON.parse(this.responseText);
 
  Ti.API.info(data);
 
for (var c=0;c<data.length;c++)
{
 
    data = Titanium.Map.createAnnotation({
        latitude:data[c]['locations'][0]['latitude'],
        longitude:data[c]['locations'][0]['longitude'],
        title:data[c]['locations'][0]['street'],
        subtitle:data[c]['field_date'][0]['value']+': Starting at '+data[c]['field_stime'][0]['value'],
        pincolor:Titanium.Map.ANNOTATION_RED,
        animate:true,
        rightButton: Titanium.UI.iPhone.SystemButton.DISCLOSURE,
        myid:(c+1)
    });
 
    Titanium.Geolocation.getCurrentPosition(function(e) {
        lat = e.coords.latitude;
        lon = e.coords.longitude;
 
    var mapview = Titanium.Map.createView({
        mapType: Titanium.Map.STANDARD_TYPE,
        region: {latitude:lat, longitude:lon, latitudeDelta:0.01, longitudeDelta:0.01},
        animate:true,
        regionFit:true,
        userLocation:true,
        annotations:[data]
    });
 
    Titanium.UI.currentWindow.add(mapview);
 
});
 
}
 
};

I've been working on this today and have gotten it to work, sort of. All the JSON data gets placed in the same pin instead of multiple pins being dropped. Once I get it fully working, I'll share the code.

May also be worth asking this question in the Drupal Titanium group recently setup http://groups.drupal.org/titanium-api

Sorry I have not yet tried this so can't offer assistance yet