plugin.js

CKEDITOR.plugins.add('uploader',{
    init:function(a){
        var cmd = a.addCommand('uploader', {exec:uploader_onclick});
        cmd.modes={wysiwyg:1,source:1};
        cmd.canUndo=false;
        a.ui.addButton('uploader',{ label:'Upload an Image..', command:'uploader', icon:this.path+'images/icon.gif' });
    }
})

function uploader_onclick(e)
{
  $.modal('<iframe src="/photos" height="480" width="640" style="border:0">',{
  	containerCss:{
  		backgroundColor:'#fff',
  		padding:0
  	},
  	overlayClose:true
  });
}