Download a texture using JQuery and YQL - please have a look at it before copypasting it inside your code (remember, YQL has quotas (1000queries/h for anonymous queries), and I'm not a Three.JS expert so I'm not sure about memory leaks, too)

THREE.JS Image Loader using YQL

// Use this function like the standard THREE.ImageUtils.loadTexture

THREE.ImageUtils.loadTextureWithYQL = function ( path, mapping, callback ) {

        var image = new Image(), texture = new THREE.Texture( image, mapping );
        var me = this;
        image.onload = function () {  };
        image.crossOrigin = '';
        image.src = path;
        
        var query = 'select * from data.uri where url="'+path+'"';

        var yql = 'http://query.yahooapis.com/v1/public/yql?q=' + encodeURIComponent(query) + '&format=json&diagnostics=false&callback=?';
        
        $.getJSON(yql, function(data)
        {
            var dataUri = data.query.results.url;
            var canvas = document.createElement('canvas');;
            var ctx = canvas.getContext('2d');
            image = new Image();
            image.onload = function(){
                ctx.drawImage(image,0,0);
                texture.image = image;
                texture.needsUpdate = true;
                if ( callback ) callback( me );
            };
            image.src = dataUri;
            
        });
        
  
        return texture;
};