What's the best implementation for more than one background service in an ASP.NET application?

1. Timer Callback

   Timer timer = new Timer(new TimerCallback(MyWorkCallback), HttpContext, 5000, 5000);
   

2. Thread or ThreadPool

   Thread thread = new Thread(Work);
   thread.IsBackground = true;
   thread.Start();
   

3. BackgroundWorker

   BackgroundWorker worker = new BackgroundWorker(); 
   worker.DoWork += new DoWorkEventHandler(DoMyWork);
   worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(DoMyWork_Completed); 
   worker.RunWorkerAsync();
   

4. Caching like http://www.codeproject.com/KB/aspnet/ASPNETService.aspx (located in Jeff Atwood's post here)

I need to run multiple background "services" at a given time. One service may run every 5 minutes where another may be once a day. It will never be more than 10 services running at a time.