问题稍微有点大啊 :)
我只说和网站有关的, 我的想法是写一个浏览器插件(我用的Firefox).
1. 打开https://builder.addons.mozilla.org/;
2. 创建插件, 实现记录打开和离开google.com的时间;
main.js:

  var pageMod = require("page-mod");
  

  var self=require('self');
  

  pageMod.PageMod({
  

  include: "https://www.google.com/*",
  

  contentScriptFile: self.data.url('unload.js')
  

  });
 

unload.js

  var log=function(str){
  

  console.log(str+":"+ new Date().getTime());
  

  };
  

  log('google:begin');
  

  

  window.onbeforeunload = function() {
  

  log('google:end');
  

  };
  

  

  window.onblur = function() {
  

  log('google:blur');
  

  };
  

  

  window.onfocus = function() {
  

  log('google:focus');
  

  };
 

这样打开或离开google, Firefox console log里会有:
info: testpage: google:begin:1365735674966
info: testpage: google:end:1365735684278

1. 下面我们io/text-streams -> TextWriter把上面的时间写入log 文件里.
   logger.js

      

       var file=require('file'),
       
   
       writer=file.open(file.join('c:','xxx_log.txt'),'w'),
       
   
       log=function(msg){
       
   
       writer.write(msg+"\n");
       
   
       };
       
   
       exports.log=log;
       
   
       require('timers').setInterval(function(){writer.flush();}, 2000);
      

   用logger.js里的log方法替换掉unload.js里的log方法;

   1. 这样你读log可以得到花在google上的时间. 定时一个脚本每天晚上从log里做统计.