gistfile1.js

//Fetch file, save to cache, and attach to the passed in item.
//imageUrl: http link to image
//file: Ti File
//item: a Ti.UI.ImageView
var fetchAndCache = function(imageUrl, file, item) {
    
    var adxhr = Titanium.Network.createHTTPClient();
    adxhr.onload = function() {
        file.write(this.responseData);
        item.image = file.nativePath;
    };
    adxhr.onerror = function() {
        Ti.API.warn("Doh! There's been a problem. We're on it.");
    };

    adxhr.open('GET',imageUrl);
    adxhr.send();

};